Loading them one after another is just a waste of mouse clicks. I am making a giant orchestral template against VEP and I’m literally just clicking the same buttons over and over again. Can we do multi-select and load them in a for loop or something?
thank you! LOVE Dorico. 
As best I can tell, there is no way to do that. It would seem that the Play Mode could become significantly more efficient with the ability to copy and paste not only expression maps but also channel effects (e.g., Reverb, [volume] Maximizer, Compressor, etc.).
Now, one can create a playback template and add the needed expression maps. Then, I believe all of the expression maps will load with the playback template. I think I understand this correctly but it’s not something that I have needed to use just yet.
That’s exactly how it works. If you want to build up your own endpoints and use them to build up playback templates, create a file with exactly the players you need, load the appropriate libraries, connect everything together as you see fit (meaning with the appropriate expression maps), save the endpoints and use them. If something is wrong, open your file, correct it, and save your endpoints again. Repeat until you’re satisfied with the behavior. That is how it’s designed.
Now, if you want to do something that Dorico cannot do, ask and we will tell you exactly that 