Late to the game! But I was asked to chime in.
We use Poseidon and the Pasta curves in Mina (btw is there a similar EIP for supporting the pasta curves in the EVM?) and we already are running in production with our own parameters (yeah I know, another Poseidon variant 
) meaning that we can’t easily change them. I have some more information on the configuration we use here: proof-systems/poseidon.md at ebe59f35f5cb6bb33fc0ed3c4cb5040d8cd81247 · o1-labs/proof-systems · GitHub if that’s of interest.
My 2 cents would be: support different bundles the same way we can support different configurations for ECDSA or for SHA-2 (SHA-2-256, SHA-2-512, etc.) Perhaps the parameters used should be dictated by an argument to a poseidon function. This way it would force standardization of at least a small number of Poseidon implementations.