That format is fine. The Steinway and the CFX are wonderful sounding cpu hogs. To get around this I'd either:
1. Run VEP Server on a slave machine that also has a lot of RAM and CPU power.*
2. Run VEP Server on your Pro Tools rig with a lot of midi channels (16 per group, right?) and run as few instances of the VEP plugin as possible. It works really well as long as you have 32GB RAM if you intend to run the Synchron piano locally.
* I ended up building a machine to do this, where I can either run one powerful PC that will run Pro Tools 2018.x and VEP7 and no FX or master bus in Pro Tools during tracking (everything on my end goes through the Apollo 8 Virtual Channels) while keeping a buffer of 128 in a 24/44.1 session. When I'm ready to mix, I print stereo "virtual returns" from the Apollo: One stem for woodwinds and brass, one stem for strings, one stem for percussion, one stem for piano. When I mix it down in Pro Tools, I switch to 32 bit float, jack up the buffer, and send the stems through a good convolution reverb and the EMT 140. It's a complicated bus setup, but it works and sounds correct. I can then deliver a final stereo mix (and stems if needed) in whatever format is required.
Before I got the CFX, I used to be able to run everything (SE 1 and 3, the Epic, a piano or two, and some other winds) between two Mac Mini 6,2's with at least 2 SSDs on each machine: One Mini for running Pro Tools, the other running VEP headless via ethernet that ran ~16 channels on one instance and about 8 to 10 on a second instance. I also run Slate Drums via VEP with no lag. The piano I used before was the UVI Fazioli, which has unisons out of tune in the C6-C8 area. The CFX pretty much maxed-out the slave Mini. To make it work as before, I would have had to find another Mini 6,2 just to run the CFX. That's what drove me to build a dedicated slave machine. Sorry this was so long-winded, but these are complex setups.
I'm attaching a couple screen shots and a template of my 2018.xx orchestral setup since Pro Tools is oddly absent from the templates section. Maybe VSL will add mine. Still waiting for a version of Pro Tools with 32 MIDI channels, and not just multiples of 16 MIDI channels.
Orchestra.ptx.zip-1696491488550-w3khk.zip VEP64U0020andU0020VESPU0020setup.zip-1696491488550-gj4pt.zip