Might be only slight then - if you tap them can you hear it through the amp?
Wax-potting is pretty easy if you have a bit of time, or it’s also a good excuse to get new pickups!
Hmmm, I'd like to keep the original pickups on there TBH, they do sound great... I haven't played much guitar this week, will have to grab the Les Paul out of its case tomorrow and investigate...
Quite possibly, they squeal when they're at high volume/gain... Very unpleasant...