ASPs would proactively manage liquidity - they have visibility into the flow of funds from expiring pool transactions, and would likely pursue lines of bitcoin credit to bridge times of low expiration flow.

The ASP can also manage liquidity fees to discourage users from making high liquidity requirement payments in times like that. For example spending large vTXOs costs more liquidity than spending small, so the ASP may encourage users to consolidate their small vTXOs to make payments at times of low liquidity. Opposite of on-chain bitcoin in that way where ASP fees being high means its time to consolidate, and ASP fees being low means it's time to consume large "costly" vTXOs.

The ASP cannot RBF, but could CPFP or pay a miner out of band to include a stuck coinjoin transaction.

Interesting - so the (slightly) larger on chain size is more than compensated for in your mind by the flexibility?

IIUC these two can do everything that APO + CTV can do with just a few "extra" witness bytes in typical usage, and TXHASH+CSFS can also do many things that CTV+APO cannot.

The vTXOs that would have been consumed and created by that coinjoin round are not consumed and not created. For the round to fully fail the ASP probably needs to spend the input they were planning to use in that round in another on chain transaction, which then gives the participants certainty that the coinjoin will never happen, and frees them up to spend their vTXOs in another round.

I believe op_ctv's byte-efficiency would be greatest, but not positive.

Do you have concerns around the potentially centralizing effects of ASPs?

Do you foresee bitcoin moving to larger blocks in the future?

What's the greatest challenge you see to developing Ark (aside from CTV activation)?