No, i don’t use them but i see them in car body shop. U-pol make good one’s from what i read.
I like more a thick resin finish coat with a flat sand and only a light 1K acrylic varnish spray if i touch top of fiber here and there when sand. Look at Resinhead build thread he show amazing finish he do with 2k polyurethane can.
Depends on what part of the world you are in, but water bourne varnishes are less likely to turn amber. Although you may never notice it over wood. I still prefer a tile and floor sealer like Behr, which can be sprayed or wiped. Two coats and it is fortified Acrylic. I have actually used this on exterior wood with no yellowing and excellent resistance to weather.
May be floor sealer will not be enough thickness to hide those birn through no?