Playing DW20 pack, getting about 60 FPS. If the Quantum Bag is in my hotbar, and I scroll so that I'm holding it, my frame rate drops to around 10 FPS the entire time I'm holding it.

I almost gave up on the pack because I couldn't figure out why it had suddenly become so unplayable. The bag isn't even full, it has about 15 items in it.

Playing with the latest version. If there's any other info I can provide to narrow this down, let me know.