I didn’t understand where the space/stage templates are. When I click the button, the stage is empty. Is there a button to load e.g. an orchestral template ?
It might be that your playback template does not define a space template, or it might be that your expression map/percussion map doesn’t use stage templates (by default this is only turned on for Dorico’s built-in expression maps).
Oh, I’m using John Barron’s template for BBCSO core. It’s an existing project. No way to get an standard symphonic orchestra template disposition ?
You will need to turn on the checkbox in the expression map(s) you are using, then you can apply a stage/space template.
However, it might be that the BBCSO sounds are already recorded with natural reverb/panning (I don’t know, I’m not a BBCSO user) so adding extra reverb/panning from the stage/space template may or may not give you the results you’re after.