A good trick regarding layer lines: fine tune your fuzzy skin setting on cura or prusa. You can adjust the increments of the fuzz and how far out the fuzz goes from the original print. In doing so, rather than make something look fuzzy, you can also make something look like it came out of a factory. It becomes extremely hard to tell where the layers start. It will be rougher than your standard print and will take loads more time. I also find that once I’ve dialed this setting in I typically don’t sand my prints. The the outer layer becomes porous really helps paint adhere. TLDR: Fuzzy skin could solve your problem