Hey guess, did you know that if you make a stone's [IMPACT_FRACTURE] 5000000, it becomes unmineable? You could edit the stone_template in the material_template_default file to that setting, then make specific exceptions in the material_stone file for soft stones like chert.
Ignoring any unforeseen consequences, this solves a lot of things. It makes it so you can dig through soil and make warrens, without being able to dig through solid stone. It makes it so you CAN make a few rare things from stone, but to do so you have to explore existing caves and caverns to find the 'soft' stone that can be so used (I'd argue, for the sake of Aztec Kobolds, that obsidian should count as something you can use). It also makes it so even if you can't harvest stone, you can still harvest gems, because Kobolds love shinies.
Encourages settling in caves, an option that wasn't really viable until this new, much-expanded cave system was added.
All things to consider.
Of course, in the end, everyone's Kobold Camp experience is merely based on a template, with changes made as they prefer them. We just need to make a majority-agreeable template, that's all.
Also, are Kobold furs brown, grey or just hairless. I could never come to a conclusion.
According to who?
The game paints them as small wrinkly brownish creatures, but I always pictured them (and thus, drew the associated Kobold Camp character set) based on them having very short, fuzzy gray fur.