Caching the cit on the itemstack should yield much better performance in theory.

Findings:

Specs: 
    CPU: i5 9600KF @4.8GHz
    GFX: RTX 2080 Super

Loaded:
    CITs:  5843
    Packs: 8

Running with 2 chunk render distance in a flat world looking directly up and 
into a chest that has unique cit items and non cits items scattered.

Observations:
    REALTIME vs EVERY TICK caching:
        Added ~10 fps in the dev environment(running in debug mode).
    More than EVERY TICK caching:
        Not noticeable but boost is there, got an extra ~2 fps on average between every tick vs every 100 ticks.
        I don't believe high caching intervals would be necessary on mid to high end pcs.

Dont have a lower end pc to test this on sadly but in theory, the more cits there are + the slower the cpu, the more effective higher cache intervals should be.

If anyone stumbles across this issue and would like to make a findings report, feel free to do so. Use the format above and run in a clean setup(no background tasks or unpredictable things happening in the game, preferably with low render distance).

The cache should be cleared on interval to fix inconsistencies.

Make it configurable to allow faster computers to get cits in realtime and slower computers to lazily cache the cits.