I’ve been exploring this as well. It works fine for many cases but not mine unfortunately.
Adding details in case devs are listening…
For example, I have a long winding car tunnel section. If do a merge and convert it Nanite I get a lot of glitchy flickering geo and it also doesn’t seem to build distance fields for Lumen correctly. I can try to merge smaller chunks but it starts to defeat the purpose at some point.
I tried to automate that process by creating a Blutility that would merge small portions of a complex spline mesh, convert it to Nanite and place back in the level. Unfortunately I couldn’t find anyway to access the “Merge Actor” features in Blutility (just “Merge Mesh Actors”).