Steps to reproduce:

1. get a pack with HEI, loliASM, GTCEu and their dependencies (i took nomi ceu nigtly and disabled every other mod for this test)
2. open loliasm.cfg and make sure releaseSpriteFramesCache is true (it probably is)
3. make a world
4. fill your bookmarks with items that have textures that take a while to generate like fluids and buckets
5. ALT+F3
6. open the inventory and see a lag spike
7. close the inventory and wait a second or two
8. open the inventory and see a lag spike
   https://spark.lucko.me/JgJm59XOBs
   
9. set releaseSpriteFramesCache to false and restart
10. join a world and repeat 5-7
11. open the inventory and see no lag spike
    

Logs:
logs.zip

This was broken in this commit: 8b42398, will be fixed.