[codefox1]

It has a lot to do with the humidity, and just how thirsty the wood is. I hope we're talking hardwood veneer that is firmly attached here otherwise nothing will make any sense. Sealer and grain filler are theoretically not the same thing and that's where all the opinions start

Think of it as installing or renewing grout on your shower wall, or if you will, the highway department patching up potholes in the road. Clean out everything, apply the filler and remove the excess. Shouldn't be able to tell where the hole was in a reasonable amount of time. No?

If you are putting too much on or thinning it too much, and then wiping all of it off and too soon, no harm done, but too heavy a coat might get you into trouble as in grinding through the veneer later on.

On a really marginal cabinet with serious flaws and not otherwise a candidate for new veneer I have used artist oils, and shellac because it dries fast, fills up voids, levels well, does not produce witness lines, and is a great candidate for a french polish job if you have the patience. If not, and you give it some tooth with very fine abrasion lacquer will usually bond OK.

Of course we could just epoxy an even larger flower pot base to cover the flaw. Yeah, that'd work.