Just gonna write this as I come up with it...
Bone is no longer an item type, but its still a material. You should be able to use it for blocks. Give the following a try:
[PRODUCT:100:1:BLOCKS:NONE:GET_MATERIAL_FROM_REAGENT:A:BONE] <- replace A with whatever reagent is bones.
[PRODUCT:100:1:BLOCKS:NONE:CREATURE_MAT:CAT:BONE] in case the above doesnt work
As for reagents, put a reaction class tag in the bone, hoof, etc material templates (much like leather and fat have) then use
[REAGENT:A:1:NONE:NONE:NONE:NONE][REACTION_CLASS:BONE] replace BONE with what you have for reaction class.
This should take bones and produce bone blocks. If you use this method though, its gonna see blocks as a reagent as well. You may have to make a fake bone material and use that for the product, also much like leather works.
So, copy the bone template, call it BONE_BLOCK_TEMPLATE or something, and add
[MATERIAL_REACTION_PRODUCT:BONE_MAT:LOCAL_CREATURE_MAT:BONE_BLOCK]
to the block bone template.
Then, we gotta add the bone block material to the creatures, else the game gets confused. Add this line
[ADD_MATERIAL:BONE_BLOCK:BONE_BLOCK_TEMPLATE]
to 'b_detail_plan_default' under [BODY_DETAIL_PLAN:STANDARD_MATERIALS]
For the reaction, reagents and product would be:
[REAGENT:A:1:NONE:NONE:NONE:NONE][REACTION_CLASS:BONE]that last one may be redundant now...
[HAS_MATERIAL_REACTION_PRODUCT:BONE_BLOCK]
[PRODUCT:100:1:BLOCKS:NONE:GET_MATERIAL_FROM_REAGENT:A:BONE_MAT]
Look up Shoastshouls modding guide if it something doesnt work. Put it on dffd if you get it to work, ill add to the make-meat-blocks mod, hehe.
Edit: whoops name typo.