Update: After many hours experimenting and procrastinating at work, I've finally devised a solution that might be of general use to others.
I didn't like the EBO idea, because
A) I'd have to mod every single creature's raws. And do so in a sometimes ridiculous and ugly fashion, like for sperm whales, modding in "[EBO:blah blah][EBO: blah blah][EBO:blah blah]" times like... 300.
B) Even then, it wouldn't scale correctly to adults vs. children, or different individual sizes.
So I tested a few dozen other things, and just now figured out:
[BUTCHER_SPECIAL:SLAB:NONE]
It makes slabs, as in the furniture item, of meat upon butchery. Slabs have no subtypes so the bug is circumvented. They are called slabs which sounds perfectly reasonable for meat, and they successfully allow stacks of themselves, unlike, say, globs. They also cannot be placed in stockpiles, since there's no stockpile for slabs made out of meat, so they won't end up in silly looking places. Craftshops won't engrave them as an option. And for some awesome reason, you can't build them either. So there's no weird behavior, just butcher products called "yak meat slabs [10]" which you can then use in reactions.
Since they aren't meat items, there is no implied edibility raw (which was the primary goal), so you can force people to do additional processing steps.
Rotting will not occur, however I have had some success replacing vanilla rotting with giving muscle tissue a heat damage point of 10,008 urists (USDA refrigeration safety cutoff hehe). Which gives you usually about a week to process them before they self destruct. Which seems reasonable. If there were some way to give inanimate objects a starting temperature (similar to creature HOMETHERM) then I could adjust the "rotting" time by making them start out cold and adjusting specific heat for the fuse length, but alas there does not seem to be. A week is okay (in super hot climates outdoors it's more like 3 days)
This doesn't work for organs as well, but I don't really care. I can just ignore organs and have it abstractly seem like it's just including those as "meat" and adjust recipe ratios to compensate.