you don't need get all the blocks to detect the changes, only the modulo
20160 blocks, which include the full dynafed headers

the blocks in the middle only have the compact parameters

all the modulo 20160 blocks (epoch length) have the full parameters,
the blocks in the middle could have either full or compact, but really
doesn't matter

also change only happens aligned with the epoch (modulo 20160) so just
checking for those jumps you'll know if there was a change or not

if you wanna follow the update and see if it's gonna happen or not,
you can follow the proposed part of the header, which is always full,
and if 4/5 of the headers in the epoch have the proposal, there's gonna
be a change

1517040 dynafed activation, no actual change since pre-dynafed era,
that's also why the block is not 20160-aligned
1753920 first dynafed transition (pak update)
1895040 second dynafed transition (signblockscript update)
2197440 third dynafed transition (fedpegscript update, segwit pegin
activation, old peg-in addresses become invalid)
2620800 fourth dynafed transition (signblockscript update)

all the updates include the 4 fields, (signblockscript, fedpegscript,
max_sig_size and pak), but not all of them change in all the updates

the first fedpegscript comes from this
descriptor, but it is not miniscript valid
sh(wsh(or_d(multi(11,020e0338c96a8870479f2396c373cc7696ba124e8635d41b0ea581112b67817261,02675333a4e4b8fb51d9d4e22fa5a8eaced3fdac8a8cbf9be8c030f75712e6af99,02896807d54bc55c24981f24a453c60ad3e8993d693732288068a23df3d9f50d48,029e51a5ef5db3137051de8323b001749932f2ff0d34c82e96a2c2461de96ae56c,02a4e1a9638d46923272c266631d94d36bdb03a64ee0e14c7518e49d2f29bc4010,02f8a00b269f8c5e59c67d36db3cdc11b11b21f64b4bffb2815e9100d9aa8daf07,03079e252e85abffd3c401a69b087e590a9b86f33f574f08129ccbd3521ecf516b,03111cf405b627e22135b3b3733a4a34aa5723fb0f58379a16d32861bf576b0ec2,0318f331b3e5d38156da6633b31929c5b220349859cc9ca3d33fb4e68aa0840174,03230dae6b4ac93480aeab26d000841298e3b8f6157028e47b0897c1e025165de1,035abff4281ff00660f99ab27bb53e6b33689c2cd8dcd364bc3c90ca5aea0d71a6,03bd45cddfacf2083b14310ae4a84e25de61e451637346325222747b157446614c,03cc297026b06c71cbfa52089149157b5ff23de027ac5ab781800a578192d17546,03d3bde5d63bdb3a6379b461be64dad45eabff42f758543a9645afd42f6d424828,03ed1e8d5109c9ed66f7941bc53cc71137baa76d50d274bda8d5e8ffbd6e61fe9a),and_v(v:older(4032),multi(2,03aab896d53a8e7d6433137bbba940f9c521e085dd07e60994579b64a6d992cf79,0291b7d0b1b692f8f524516ed950872e5da10fb1b808b5a526dedc6fed1cf29807,0386aa9372fbab374593466bc5451dc59954e90787f08060964d95c87ef34ca5bb)))))

the second one is miniscript valid and
you can convert it using hal or similar
wsh(or_d(multi(11,020e0338c96a8870479f2396c373cc7696ba124e8635d41b0ea581112b67817261,02675333a4e4b8fb51d9d4e22fa5a8eaced3fdac8a8cbf9be8c030f75712e6af99,02896807d54bc55c24981f24a453c60ad3e8993d693732288068a23df3d9f50d48,029e51a5ef5db3137051de8323b001749932f2ff0d34c82e96a2c2461de96ae56c,02a4e1a9638d46923272c266631d94d36bdb03a64ee0e14c7518e49d2f29bc4010,031c41fdbcebe17bec8d49816e00ca1b5ac34766b91c9f2ac37d39c63e5e008afb,03079e252e85abffd3c401a69b087e590a9b86f33f574f08129ccbd3521ecf516b,03111cf405b627e22135b3b3733a4a34aa5723fb0f58379a16d32861bf576b0ec2,0318f331b3e5d38156da6633b31929c5b220349859cc9ca3d33fb4e68aa0840174,03230dae6b4ac93480aeab26d000841298e3b8f6157028e47b0897c1e025165de1,035abff4281ff00660f99ab27bb53e6b33689c2cd8dcd364bc3c90ca5aea0d71a6,03bd45cddfacf2083b14310ae4a84e25de61e451637346325222747b157446614c,03cc297026b06c71cbfa52089149157b5ff23de027ac5ab781800a578192d17546,03d3bde5d63bdb3a6379b461be64dad45eabff42f758543a9645afd42f6d424828,03ed1e8d5109c9ed66f7941bc53cc71137baa76d50d274bda8d5e8ffbd6e61fe9a),and_v(v:older(4032),multi(2,03aab896d53a8e7d6433137bbba940f9c521e085dd07e60994579b64a6d992cf79,0291b7d0b1b692f8f524516ed950872e5da10fb1b808b5a526dedc6fed1cf29807,0386aa9372fbab374593466bc5451dc59954e90787f08060964d95c87ef34ca5bb))))

and if you look in the coinbase tx from the
first proposal, you can see the cleartext version
https://liquid.network/block/002c4e4e2fa1a4ea6458c7e539fd43a64a859522207b08d88fc13fb13015c4d7


local example: $ elements-cli getrawtransaction
79feef1b463ec3c1f1c7090351a391c63ac113a0e5d7130e9b9c012c64fbf3c6 1
002c4e4e2fa1a4ea6458c7e539fd43a64a859522207b08d88fc13fb13015c4d7 | grep
"OP_RETURN 4" | cut -d: -f2 | tr -d '",' | cut -d " " -f3- | while read
line; do echo $line | xxd -r -p; echo; done
BLKSwsh(multi(11,026a2a106ec32c8a1e8052e5d02a7b0a150423dbd9b116fc48d46630ff6e6a05b9,03326b356f7ad58556815a3ab2e606789bc5b5d10c2f38ebc7fb4c5692a0d3cfa0,02888bda53a424466b0451627df22090143bbf7c060e9eacb1e38426f6b07f2ae1,02aee8967150dee220f613de3b239320355a498808084a93eaf39a34dcd6202485,02d46e9259d0a0bb2bcbc461a3e68f34adca27b8d08fbe985853992b4b104e2741,02e9944e35e5750ab621e098145b8e6cf373c273b7c04747d1aa020be0af40ccd6,02fd491b501cd9a5c60d98c27d54dda0ae46a70f349c3e5337a3394807efead53b,033b421566c124dfde4db9defe4084b7aa4e7f36744758d92806b8f72c2e943309,0353dcc6b4cf6ad28aceb7f7b2db92a4bf07ac42d357adf756f3eca790664314b6,037f55980af0455e4fb55aad9b85a55068bb6dc4740ea87276dc693f4598db45fa,0384001daa88dabd23db878dbb1ce5b4c2a5fa72c3113e3514bf602325d0c37b8e,039056d089f2fe72dbc0a14780b4635b0dc8a1b40b7a59106325dd1bc45cc70493,0397ab8ea7b0bf85bc7fc56bb27bf85e75502e94e76a6781c409f3f2ec3d112219,03b00e3b5b77884bf3cae204c4b4eac003601da75f96982ffcb3dcb29c5ee419b9,03c1f3c0874cfe34b8131af34699589aacec4093399739ae352e8a46f80a6f6837))#jpp3v2su
FDPGwsh(or_d(multi(11,020e0338c96a8870479f2396c373cc7696ba124e8635d41b0ea581112b67817261,02675333a4e4b8fb51d9d4e22fa5a8eaced3fdac8a8cbf9be8c030f75712e6af99,02896807d54bc55c24981f24a453c60ad3e8993d693732288068a23df3d9f50d48,029e51a5ef5db3137051de8323b001749932f2ff0d34c82e96a2c2461de96ae56c,02a4e1a9638d46923272c266631d94d36bdb03a64ee0e14c7518e49d2f29bc4010,031c41fdbcebe17bec8d49816e00ca1b5ac34766b91c9f2ac37d39c63e5e008afb,03079e252e85abffd3c401a69b087e590a9b86f33f574f08129ccbd3521ecf516b,03111cf405b627e22135b3b3733a4a34aa5723fb0f58379a16d32861bf576b0ec2,0318f331b3e5d38156da6633b31929c5b220349859cc9ca3d33fb4e68aa0840174,03230dae6b4ac93480aeab26d000841298e3b8f6157028e47b0897c1e025165de1,035abff4281ff00660f99ab27bb53e6b33689c2cd8dcd364bc3c90ca5aea0d71a6,03bd45cddfacf2083b14310ae4a84e25de61e451637346325222747b157446614c,03cc297026b06c71cbfa52089149157b5ff23de027ac5ab781800a578192d17546,03d3bde5d63bdb3a6379b461be64dad45eabff42f758543a9645afd42f6d424828,03ed1e8d5109c9ed66f7941bc53cc71137baa76d50d274bda8d5e8ffbd6e61fe9a),and_v(v:older(4032),multi(2,03aab896d53a8e7d6433137bbba940f9c521e085dd07e60994579b64a6d992cf79,0291b7d0b1b692f8f524516ed950872e5da10fb1b808b5a526dedc6fed1cf29807,0386aa9372fbab374593466bc5451dc59954e90787f08060964d95c87ef34ca5bb))))#7jwwklk4

$ elements-cli -rpcwallet=nopriv importdescriptors '[{"desc":
"wsh(multi(11,026a2a106ec32c8a1e8052e5d02a7b0a150423dbd9b116fc48d46630ff6e6a05b9,03326b356f7ad58556815a3ab2e606789bc5b5d10c2f38ebc7fb4c5692a0d3cfa0,02888bda53a424466b0451627df22090143bbf7c060e9eacb1e38426f6b07f2ae1,02aee8967150dee220f613de3b239320355a498808084a93eaf39a34dcd6202485,02d46e9259d0a0bb2bcbc461a3e68f34adca27b8d08fbe985853992b4b104e2741,02e9944e35e5750ab621e098145b8e6cf373c273b7c04747d1aa020be0af40ccd6,02fd491b501cd9a5c60d98c27d54dda0ae46a70f349c3e5337a3394807efead53b,033b421566c124dfde4db9defe4084b7aa4e7f36744758d92806b8f72c2e943309,0353dcc6b4cf6ad28aceb7f7b2db92a4bf07ac42d357adf756f3eca790664314b6,037f55980af0455e4fb55aad9b85a55068bb6dc4740ea87276dc693f4598db45fa,0384001daa88dabd23db878dbb1ce5b4c2a5fa72c3113e3514bf602325d0c37b8e,039056d089f2fe72dbc0a14780b4635b0dc8a1b40b7a59106325dd1bc45cc70493,0397ab8ea7b0bf85bc7fc56bb27bf85e75502e94e76a6781c409f3f2ec3d112219,03b00e3b5b77884bf3cae204c4b4eac003601da75f96982ffcb3dcb29c5ee419b9,03c1f3c0874cfe34b8131af34699589aacec4093399739ae352e8a46f80a6f6837))#jpp3v2su",
"timestamp": "now"}]'
[
  {
    "success": true
  }
]

$ bitcoin-cli -rpcwallet=nopriv importdescriptors '[{"desc":
"wsh(or_d(multi(11,020e0338c96a8870479f2396c373cc7696ba124e8635d41b0ea581112b67817261,02675333a4e4b8fb51d9d4e22fa5a8eaced3fdac8a8cbf9be8c030f75712e6af99,02896807d54bc55c24981f24a453c60ad3e8993d693732288068a23df3d9f50d48,029e51a5ef5db3137051de8323b001749932f2ff0d34c82e96a2c2461de96ae56c,02a4e1a9638d46923272c266631d94d36bdb03a64ee0e14c7518e49d2f29bc4010,031c41fdbcebe17bec8d49816e00ca1b5ac34766b91c9f2ac37d39c63e5e008afb,03079e252e85abffd3c401a69b087e590a9b86f33f574f08129ccbd3521ecf516b,03111cf405b627e22135b3b3733a4a34aa5723fb0f58379a16d32861bf576b0ec2,0318f331b3e5d38156da6633b31929c5b220349859cc9ca3d33fb4e68aa0840174,03230dae6b4ac93480aeab26d000841298e3b8f6157028e47b0897c1e025165de1,035abff4281ff00660f99ab27bb53e6b33689c2cd8dcd364bc3c90ca5aea0d71a6,03bd45cddfacf2083b14310ae4a84e25de61e451637346325222747b157446614c,03cc297026b06c71cbfa52089149157b5ff23de027ac5ab781800a578192d17546,03d3bde5d63bdb3a6379b461be64dad45eabff42f758543a9645afd42f6d424828,03ed1e8d5109c9ed66f7941bc53cc71137baa76d50d274bda8d5e8ffbd6e61fe9a),and_v(v:older(4032),multi(2,03aab896d53a8e7d6433137bbba940f9c521e085dd07e60994579b64a6d992cf79,0291b7d0b1b692f8f524516ed950872e5da10fb1b808b5a526dedc6fed1cf29807,0386aa9372fbab374593466bc5451dc59954e90787f08060964d95c87ef34ca5bb))))#7jwwklk4",
"timestamp": "now"}]'
[
  {
    "success": true
  }
]

The above FDPG descriptor points to the peg-in address
bc1qxvay4an52gcghxq5lavact7r6qe9l4laedsazz8fj2ee2cy47tlqff4aj4 used
by Liquid.