Improving the nose rests on my glasses.

[DaveP]

Much depends on what type of lenses you have. Imperfect alignment never used to make much difference to me, but since being moved on to variable focus - well things have changed! Lateral displacement or tilting of the lenses now has a marked effect. I wouldn't dream of deliberately deforming the frame.
However, splayed cushions and a tendency to slip down a sweaty nose under vibration are also detrimental to good vision and a bit of something under the bridge is the most reliable solution IMO. I wouldn't want to wear specs with frame tensions strong enough to do the job. There's only so much pain I'm willing to put up with!