There is a inconsistency in the
butchery workshop in that creepy crawlers are extremely small (with a size of a 1000 like other vermin creatures) but are butcherable within a trapping cage with the "extract" job contradicting the practice of normal butchery which
comparably would run with a lot less bugs with a properly adjusted system.
- Given its possible to obtain cuts of vermin animals from trade & the embark screen, tags like [BUTCHERABLE] for vermin especially could be employed to distinguish edible ones from ones intended to either not be eaten (no acorn fly BP materials appearing by accident in worldgen) which are then marked as valid for vermin butchery jobs like the crawler example, fish alternatively could have [INEDIBLE] tags also for species like jellyfish with nothing to eat
Extraction & food would be good to separate on different grounds, much least for the future also for extracting extractables from larger creatures without first conflicting to look around for vermin to cut apart with a dissector. And given the efficiency of the vermin extraction, we could emulate the requirements of this code used in crawler butchery.
The second conclusive part of my suggestion is about a rework of how butchery operates upon its reagent materials, currently the skill of the butcher only applies to the speed of the butchery whilst dead, my counter suggestion to this is that
through practice a butcher with improved skills eventually winds down the effective rate that they can butcher a animal in its entirety all the way to [size:10] at legendary level.
Therefore if you want to have a proficient meat industry with small efficient animals (or large in extreme detail) or butcher poultry effectively along with eggs, invest into a butcher dwarf and make a return on your small animals. Crundles for instance have lots of useful materials (horns, scales etc) but because of their size most of these are quite small and are not reclaimed.
- Rabbits are a perfect example for meat industries in cold climates, upon finding a suitable grazing pasture underground, in which they breed fast and consume little grass, you could eat them for food, use their bones & their often unseen unique insulating fur for cold protective yarn.
- On a more serious note a additional incentive for having these changes is because certain small BP components are entirely unobtainable for mandates & play that the game doesn't actively recognize are also unreasonable to get since in game logic its feasable but mechanically impossible.
Animal dissectors are already trained in focusing on cutting apart small animals so would require no vital change.