Tinkered with it a bit today and from what I can tell it does a decent job.
I used ASIOLinkPro to route Dorico’s audio into Cubase.
Loaded TXL into Dorico and set Midi Output to my virtual port.
Set up Cubase to slave to MTC/MMC from said virtual port.
Set up an audio track to record Dorico and hit play in Dorico. I let a few seconds record so I could get an idea ‘exactly’ where on the time-line Dorico begins playing. After recording a bit I stopped Dorico, selected the audio part in Cubase and tapped l, which snaps the cursor to the beginning of the part. The cursor info now lets me know the Project Start Time and Display Time offsets I need in the Cubase Project.
Now I seem to have an instance of Cubase with its transport synced up with Dorico.
