I had the texture pack Clear Craft enabled when I loaded my world into 1.15.0.51 and was met with unbearable lag. I determined that the cause was not from my map wall or too many animals. The map wall screen shot is in my base after I significantly reduced my live stock numbers, down to 2 of each. I went to a village that has spawned 30-50 villagers, second screen shot, and the game operated basically normal with Clear Craft active. It seems to work long as I was far enough away from my base for it to not render, 6 chunks is my render distance. With no texture packs enabled it is running great, 50-60 fps, third screen shot. I think it could be a combination of my automated smelter and my some 20-30 chests, most are over half full.