Can we make universality transitive in SnarkyJS/pickles/kimchi?

[bkase]

Mina’s L1 supports universality in the zkapp cpu his kimchi/pickles . Can we tap into universality at the programmable module layer? Can we define a recursive circuit in snarkyjs that can verify proofs of older versions of itself?
This would allow upgrades of the zk circuit during recursive aggregation without having to settle to the L1 in between.

Why:
Having this feature would make it more practical to build cross-communicating zkAppChain rollups + allow SnarkyJS/Kimchi to be directly used as the core for other recursively composable platforms like they can on the Mina L1 (L2s, L3s, L4s, etc that settle on Mina for example)

[mimoo]

we could easily do this now, but depending on the changes in the proof system it might become less and less "easy" and more and more of a nightmare. Basically, we will either have to fork the verifier circuit every time we do a breaking change in the proof system, or if we can, make the verifier circuit more general depending on configuration.

EDIT: rereading the question I'm not sure I fully understand it actually

[bkase]

Slack discussion yielded yes on the pickles backend side using side loaded verification keys -- the work becomes how do we expose this in SnarkyJS with a nice API

[bkase]

And this is already tracked here! #673