Title. Add a version using the old 1.12.2 textures for old blocks. Maybe giving new blocks old textures here but mabye not. Some of us prefer programer art and it wouldnt take that much effort to just put all the old 1.12.2 textures into a resource pack or config option.

I dont know if this is feasable but could you just modify the textures a bit for said new models? I wouldnt imagine this would be too hard but it would depend on how different the model was.

Huh? The mods only out for 1.12? Confusion

for When the mod eventually updates to 1.16.x or 1.17.x

Could have made that more clear haha, and it's unlikely as we've got new block models too which wouldn't be compatible with the old textures, nothing stopping resource packs from modifying this though

There are no plans for a feature like this at the moment, sorry!