Indeed , actually it is quite common to use MiniDsp/MSO connected to Trinnov. Some people do it to save channels, some for MSO functionality.For MSO you need to be able to calibrate the subwoofers as one with the MSO PEQ already applied (if you want the optimizer to flatten the response and let MSO just minimize the seat to seat variation). With MSO being free, though, it's surprising Trinnnov doesn't have something at least on par with it. After all, better bass integration is probably one of the more noticeable things you can improve in a system by digital means.
Actually as I see it - with 2 subs, it does not make too much of a difference, MSO also can not work miracles, with 3 or more properly placed subs most of the issues take care by themselves anyway. I have kind of Geddes style sub placement and there is not much to do except of this one persistent room mode at 29hz that I PEQ manually prior to calibration. Combine this with properly treated room (membrane resonators) and you are OK.
As I understand it from Trinnov guys - they do not want brute force solution like DLBC or MSO. So let’s see.