Could we reasonably pass that information on when relaying after accepting to the mempool though? We’d need to either recognise that the latter chunk pays DoS-fees for the higher-priority chunk; or we’d need to track “orphaned for DoS reasons” collection and retry chunks when high-fee child chunks are announced?
Just seems like something we could easily skip initially and introduce later as an improvement if warranted – it’s not a regression, and probably not likely to be particularly common? KISS, etc.
(I agree that it seems feasible and there are cases where it would be useful if it worked reliably)