For those looking to temporarily change UR to not cure Hardly Poisoned at All, the necessary surgery is on lines 1580 and 1581 of the script:
Code:
return beset($effects[Hardly Poisoned at All, A Little Bit Poisoned, Really Quite Poisoned,
Somewhat Poisoned, Majorly Poisoned]);
if you take out "Hardly Poisoned at All, ", all your other recovery bits will keep working, without curing that level of poisoning.
If you have a hottub, it still may cure your poison incidentally, but it'll no longer do so at the beginning of every fight.