raydarkhorse your not paranoid.
The only excuse for two compasses is you just lost your third.
I must be; carry three compasses AND a GPS.

It seems every plastic liquid filled I have or ever owned develops a bubble.

At least the lensatic can't do that.

Seriously unless it's large the compass will function correctly.
I wouldn't heat it very much, maybe a little indirect solar heating in a window.

Good luck.