Sure the way we used to do this in the past was by just using a randomish texture that was a black texture with 3-4 random white blurry dots in various places. Then you can just use “reflection Vector” and component mask the XY, and use that as the UV’s of the reflection texture. Then you add it to the material as either basecolor or emissive additive. The down side is that it will be completely unshadowed by any moving lights or shadow casters. Doing it in the base color will hide that better but you won’t get as raw of color control as doing it in emissive, so maybe try both and play around.
You can simulate roughness by using “Mip Bias” and using the roughness texture of the underlying asset to boost the mips of the reflection texture. And then of course you may choose to multiply it by a specular color mask.