I usually tolerate just the very minimum, if at all. If the effect is at all audible or if the arm shows significant up/down movement then that would be a no-no for me. Have to say, haven’t had too much of a problem with this on audiophile issues of the last few years, it was more of a problem with those thin 70s/80s e.g. ABC Impulse, Savoy, Atlantic, Inner City etc.. There seem to be lots of warp reports on the Hoffmann Board, maybe I have been lucky.
On recent issues, I don’t think I have had a single issue with warping on Blue Note Tone Poet, Classics or Music Matters. A pretty good record.
Some of the worst warping I ever saw were from cheap US cutouts I bought in the 1970s, including some Liberty Blue Notes, Motown, Stax and Atlantics. The rumour was that these were used as ballast in shipping between NYC and Liverpool, then sold for a pittance to the big UK chains. I wouldn’t be surprised if Morris Levy was behind it, nor if they had been stored in or near the ship’s boiler room !