I decided to see how the migration from Compatibility to Voxel works, and noticed that it adds a BloomEffect set to Intensity=0 to avoid strange light reflections from smooth objects, which is basically correct.
Converted in new studio
Created in old studio
But it breaks the neon. Increasing the BloomEffect can cause unwanted extra light. In the old days (with legacy technology), the neon material worked a little differently, it had a blur(?) applied to it. Overall, the old neon looks stylistically nice, and this once again makes me think about custom shaders for Roblox.
Deleted BloomEffect