These geometry types don't work properly with attributes currently, so the persistent base isn't really "persistent" and doesn't last after exiting sculpt mode, but it's still useful for it to work within a sculpt session. Enable that by adding temporary array storage in `SculptSession`. During the sculpt refactor project I mistakenly assumed that this didn't work well enough that anyone would use it. Pull Request: https://projects.blender.org/blender/blender/pulls/133410