You should not have the CPU issue with VSTi. Do you have a midi loopback somehow (although not sure how since you are using VST).
It shouldn’t, since in this case the plugins are simply inserted in the VSTi rack in Dorico. The player itself shouldn’t send MIDI messages back to Dorico, apart for the sysex required to save the plugin’s settings. The more complex routing including VEPRO is much lighter, and it should, on the contrary, be more prone to this type of accidents.
Starting with a blank project with no instruments, I can add a player - or even more efficient add an ensemble - and all the instruments, routing, expression maps, presets, etc. will get set up automatically.
Unfortunately, as I also noted in the other thread, I’m trying to use a particular setup (actually, a quite common one), where the automated setup seems not to work, or not to be granular enough.
You can of course send Dorico’s playback output to Logic as an “instrument”.
It’s my limitation, but I prefer things that work straight. Strange solutions make me feel uncomfortable. I don’t have a particularly sophisticate mind. In any case, there would be no reason to use Logic as a host, when there is VEPRO working fine with Dorico.