The tele kit I got from elsewhere as my first build had an impossibly tight pocket so a bit of careful sanding on the sides of the heel of the neck got me a good firm fit, also gave it a bit of a touch around the end of the neck to sort the misfit there as well.

The STA-1 was loose but not too bad so I lined the sides of the neck pocket with some copper shielding tape which tightened it up to the point I was happy with it.