I would think octopus would turn out very similar to the sous vide squid you already did.

I’d like to see hot dogs/bratwurst/knockwurst. It’d be interesting to see how it compares to grilled (which can turn the casing into leather) and boiled/steamed (which can give them a watery, mushy texture if overcooked).

Icelandic hot dogs are cooked in sub-boiling water with a little malt beer and have just the best texture and taste. It would be interesting to see if sous vide can recreate that combination.