Thanks for the reply.
Unfortunatley I’m one of the many users impacted by the selection tool being unusable in Pro and Make (2017 & 2018). - Selection Tool process is slow, unbearably slow - #498 by fuzz.evans
So I’m giving the online version a try which fortunately doesn’t have this really stressful problem (not blaming Sketchup specifically, but it’s a serious hinderance to productivity either way), but now I’m trying to get the other bits I use in Make/Pro to work the same way in Online.