ModelLib thumbnails

The ModelLib thumbnail seems like a cool feature,
Is it Asobo only or is there a chance to implement it for 3d party ? Can’t find anything in the documentation about (actually the screenshot and description in the docu are Vignettes while in the Scenery Editor they are called Thumbnails)
So maybe documentation bug?

I have also noticed a very slow time “Loadings…” the sceneries objects list, maybe related to that feature?
With nearly non existent Official and Community the loading should be very fast compared to 2020…