I have recently switched to using Ak Interactive intermediate Gauzy agent as an interim gloss coat. Not great for a final coat, but fine if you want to use it for decals or just to protect a coat of paint. For example I wanted to do several layers of chipping, but I wanted to protect the base layer. So I put a coat of this on before adding additional colors.

https://ak-interactive.com/product/intermediate-gauzy-agent-shine-enhancer/