I have found a couple more interesting...umm...oddities?
1. On the left side of Ensemble Pro is a list of channels, the top most one is Master Bus. Clicking on this channel, specifically the words "Master Bus" (just to be clear where exactly Im clicking, Im not clicking on any controls in the box) will generally open the mixer console. However, with MIR Pro loaded, it does not exhibit this behavior, it in fact does nothing. In order to bring up the mixer, you have to find the little Mixer tab at the bottom of Ensemble Pro. As soon as you unload MIR Pro, Ensemble will allow clicking on the Master Bus words in the channel list on the left side once more.
2. Any track that has any of the orchestral strings (there may be other instruments, but I noticed it specifically with the special edition orchestral strings violin+ and viola+ instruments from the special edition complete) that play at the beginning first 3 measure of a track and are routed through MIR Pro will not be exported when doing a File -> Export -> Audio mixdown in Cubase 10.10, UNLESS you do a real time audio export. I have created several new projects trying to track down exactly what is causing this, might have more info later this week, but this should be easily replicable.
3. Ensemble Pro does not seem to export 5.1 audio when using the File -> Export -> audio mixdown function in Cubase. I end up with a stereo file.
(This has been fixed) Finally, Ensemble Pro does not recognize Vienna Suite or Vienna Suite Pro. in the mixer channel of Ensemble Pro, clicking on the FX dropdown, MIR Pro is listed, not Vienna Suite/Vienna Suite Pro. (Thanks for the assist bogdan)