That would be a shame considering the cabbage you paid for the paint.
I used Timbermate to fill around some gaps when I re-dowelled my Squier neck.
I left it to dry for ages and sanded it nice and smooth.
It didn't shrink until after the paint had dried, so it was the paint that triggered the shrinkage.
FWIW most of what I point out on this forum tends to pan out as complete bollocks (I've adjusted for that in my avatar) so hopefully
you can safely disregard my input.
cheers, Mark.