"each pool will be submitting ~15k vB to mempool every 10 minutes (so there's a limit for number of pools running at the same time - if my math is correct there can be AT MOST 256 pools). But also note here that the numbers are just a suggestion here, the "5 seconds" could change to e.g. 1 minute."
256 pools will utilize all the bitcoin tx throughput... and fixing it only a bit by waiting 1 minute for transaction to happen instead of 5 sec - is like going back from L2 to L1 "slow motion" - unacceptable user experience, then
that's mad idea at first look, imo