SpeedTree asset import data seemingly not marked editor only object

Licensee reports log spam when running editor in -game mode, complaining that a SpeedTreeImporter plugin object can't be loaded. This would be because some UObject defined by the SpeedTree editor plugin is not saved with the "editor only" flag set - when loading in -game mode, editor plugins are not loaded, and so it doesn't know the class.

We need to get a .st SpeedTree asset to try and get a repro.

Licensee reports that resaving the asset hits the UAssetImportData::IsEditorOnly, so perhaps the issue is some other SpeedTree plugin object being referenced somewhere.

As far as I can tell, this issue is not blocking; it's just generating log spam and unnecessary bloat in the asset, but it's mostly an annoyance.