I'd personally fill the wood grain to start with after which you can primary the cabinets with oil primer. Which will seal the filler, glaze, and assist the grain sample Mix in with the paint this means you don't see any flashing or an uneven finish. Don't use BIN primer. https://painting-a-cabinet81468.rimmablog.com/4688031/5-essential-elements-for-painting-over-polyurethane-cabinets