Dangers of too high voltage driver?

When I started tuning the drv8825, I was going for about 0.8V, but one of the drivers there was something wrong with the potentiometer, because when I had a reading of 0.3V and turned half a milimiter it went up to 1.5V (really) and after a very long time I got to about 0.82V, my worries is, when I start printing, because of the vibrations the screw is probably going to make the potentiometer change its voltage a bit, and because it is so sensible it may go up too high, is there any danger on a too high voltage drv? What could happen?

The driver would get very hot and probably go into thermal protection mode. That means it would stop working until it cools down. The print is ruined then.
You could use WD40 to clean the potmeter or just turn it back and forth a few times while the printer is off.

But as far as I know, WD40 would just lubricate the screw and it would turn more easely, but my problem is that it is too sensible

WD40 also contains mild acid like a contact spray. If you have contact spray, try that first.