So my idea comes from a place where I'm playing a private game with my girlfriend. We are trying to stop the asteroid and advance through the tech without doing any hunting. We'd like to be able to play the game this way as it provides extra challenges early on and also because my girlfriend is vegan and doesn't want any of the animals to be hurt.
The problem we're running into currently is when it comes to tailoring and cooking where we require specific recipes that involve animal meat or hides in order to learn the skill books. Our solution would be to have an equal value/rarity item to substitute for those, example for cooking why do we have to have the campfire roast and not the wild stew, fiddlehead salad, or any of the other items? For the tailoring what we need from the skill doesn't require any animal parts to advance to future techs but we require hides in order to learn it. I would think that tailoring should be able to learned with just the grass that is needed (maybe more of it) and the wood chips that come off the trees as that is what is needed to make the base cloths.
Ideally I think the system could be more modular and be able to use one of several items to complete the research instead of one specific one. This methodology could be applied to several of the techs. The only downside would be that some trades/skills could be skipped (butchering and hunting in our case)