The issue is that I want to use a wallet created with segwit/taproot compatible versions of bitcoind in the old version of clients.
All wallets created with new software are incompatible with older versions.
You cannot use a wallet created with the latest bitcoind in an older version of bitcoind!
Impossible!
Bitcoin Core wallets use a versioning system where you have to explicitly upgrade the wallet using an RPC call if you want it to use a newer version. They are not automatically upgraded when they are imported into a newer Core.
Even if you could manage to import the newer wallet format into an older version, the older Core versions have
no taproot or Segwit support at the consensus level.