Clear gloss Poly over satin nitro?

[John Parker]

I just bought a black double bound body with a satin nitro finish. I would
like to bring the gloss up can I spray a gloss poly over top & do I need to tape the binding or can I spray over top?

[Irwilliams]

Generally, it isn't good to mix types of finishes. You'll have all sorts of issues. The poly won't stick well.
Sometimes when you mix finishes, you'll even have a chemical reaction where it won't cure (leaving a sticky mess permanently), or will start bubbling.

https://paintsgeek.com/can-you-put-gloss-polyurethane-over-satin-answered/