Cubase 12 Pro and Transport Synchroniztion with Synfire Pro 2

I was looking into this a few weeks ago, and the word is that you will have to revert to Cubase 11 if you want to use ReWire.

I would welcome hearing about another solution if you find one, but I'm not getting my hopes up.

Without rewire support in the daw, you have to resort to virtual midi cables. These are built in on a mac but on windows you have to use something like loopbe. It is no longer sample accurate in timing but limited to the resolution of the midi clock. This was how synfire orginally had to link to a daw and midi cables have been used to drive external synths from a daw or even a master keyboard for an eternity.

Theoretically with a midi loop device like: 

loopMIDI

But I am also strugelling with that and did not get it work. Here a thread with some things tried

Before synfire switched to rewire I used to use loopbe, there is a single port version that's free for non-commercial use and a 30 port version too.

(https://www.nerds.de/en/loopbe1.html)

On a mac you can just use the virtual midi that's built into macos