Using VSL - or other playback templates

Dorico 4 … I can see a whole bunch of Playback Templates but only some of them have the “factory” icon next to them. I particularly want to try out VSL but I can’t seem to get any sound. If I try “import”, there are no files with the appropriate Dorico format that I can find.
Can anyone help please? I’m obviously being a dim-wit in some way.

Have you downloaded and installed the VSL playback templates from the VSL web site?

Well, I thought I had. Why otherwise would I be able to see the VSL items in the Playback Templates? I’ll go back and download/install them all again.

Ah! Numpty! When I downloaded VSL (yonks ago) I was sure it was a ‘trial’ package. Obviously not!! I don’t have that sort of money to shell out - as an amateur composer - so I guess I’ll stick with NotePerformer 3.

Incidentally, I’ve looked at loads of stuff about NotePerformer 4 and I can’t see for the life of me that it’s an upgrade worth doing. Any thoughts on that?

Yes, a few thoughts can be found in this thread, currently 894 posts long.