I haven't done any real diving into the tx portion of COMB yet, so I'm afraid I won't be much help here.

I ask about the block pulling because I'm curious if it makes sense to aim for, in the future, segmented orphan repair. Right now if a block is corrupted the entire chain after said block is discarded; using the current block-by-block fingerprinting, as well as including the hash of the previous block's metadata, it seems viable to allow Haircomb to just discard only the corrupted blocks, and redownload them.

I'm not sure if I'm being paranoid or making up corruption scenarios that don't exist though, so I dunno if it's actually worth doing or not right now.