Insert Effects Routing

Am I just being dumb, or does inserting an effect insert it across all instruments/channels?
Is insert effects per track, per VST instrument or across everything? When I select it it’s across all channels.

Inserts apply to the output on which they are inserted, and only that output. If you add an insert into e.g. the master output, then that insert will apply to all of the signal arriving at the master output, but if you’re adding it to an individual plug-in output then it will only apply to that plug-in.

Please feel free to describe what’s happening for you in a bit more detail and we should be able to provide some help and advice!

I guess I’m not completely clear on what an output is to Dorico. To give an example, let’s say I set up a string quartet score, using one instance of Noteperformer, or alternatively a single instance of Kontakt, with 4 instruments. Is it possible for me to insert an effect to apply to say, just the viola (e.g. ch3), or would I have to instead set the viola up in a different instance of NP/Kontakt to to that?
I’m assuming I would.

For Kontakt, provided you’re using the multi-output version of the plug-in (which is what Dorico should show you by default for VST2.x, though now Kontakt is VST3 you may need to specifically choose the multi-output version), you can insert an effect on just one output.

For NotePerformer, no, there’s just a single stereo output for the whole plug-in. I’m not sure how you could configure Dorico and NotePerformer such that one instrument goes to its own instance of the plug-in, but I suppose it’s possible by manually instantiating NotePerformer in the rack, setting the expression map in the Endpoint Setup dialog, and then routing the individual instrument in question to that new instance.

Right, I understand now. I had a feeling it would be something like that as regards Noteperformer, but it’s good to know that I can get it to work with Kontakt.