Ok! I think I got it working!
What seems to have made my Hack start in macOS with the Alpine-Ridge card installed was changing Internal Graphics from "Enabled" to "Auto"!!
So now it starts and I have been able to mount a FW drive! (via TB3 to TB2 adapter, to a TB2 to FW800 adapter then a FW800 to FW400 adapter through a FW cable and then a FW400 to FW800 adapter into the harddrive)
So if that works through that effload of adapters I feel pretty confident that a Thunderbolt device should also work
One thing: I wanted to test out with my MOTU828mk3 audio interface (FW) that I had got working in Windows via all those adapters, but after installing the MOTU drivers, the Hack wouldn't start so I had to restart from backup drive and then remove the MOTU components and extensions and then it started again.
Now I just need to buy the Apollo Twin mkII interface and hope it works!
Cheers!