For me, the freeze only happen when I use ranged weapons like guns or staffs or when the mobs use ranged weapons also. If I use melee weapons then everything works well.
I think I may have stumbled upon something that happens.
I used the following:
Unlimited Health Unlimited Mana Super Damage Ignore Skill Cooldowns Unlimited Blink and Mega Currency Drop - I activated this after picking up gold and then deactivated it immediately.
With these options active and when using a MELEE weapon like an axe, I had no problems.
However, I think there is problem when you enter a room, there is a chance that a monster will teleport outside of the room. It disappears then comes back then disappears again. When this occurs the game will slightly freeze. You can still move or blink but any action that uses a turn will cause a slowdown while the teleporting monster is acting. If this happens to many monsters you won't be able to act at all.
My solution was to use blink and axe weapon to kill enemies fast in each room. Then in the boss room the final room before you get the portal to return to your home, I activate mega currency again to pick up only 1 crystal. I enter portal to home with all the crystals and unlock upgrades.
Still doesn't work, whenever I activate it, it will freeze the game after a few turns.
Just tried it with only Unlimited health and freezes right after killing anything.