Midas Venice F32 working on High Sierra!
Here's an update on my situation;
I've reverted all the way back to El Capitan after my Midas Venice F32 still wasn't working. Even then, it didn't seemed to connect with my Macbook Pro. Also on my Windows partition (Bootcamp) it didn't connect to my Mac. I've tried daisy chaining with my Fireface 400 instead of direct connecting the Venice to my Mac, but that also didn't work.
I've went to DSA-AVL, a official Midas repair center here in the Netherlands and they replaced my whole Firewire board (β¬400). They also did the post-fader modification for me afterwards, so now my faders are controlling the volume of the firewire and direct outs.
Back home, the Midas still didn't gave a connection on El Capitan.. As a last resort I tried daisy chaining the Midas with my Fireface 400 again, and FINALLY the Midas showed up in the Midas FW Control Panel.
So, my Midas won't connect directly to my Macbook Pro with the Thunderbolt to Firewire adaptor, but will connect to my Macbook via a daisy chain with the Fireface 400.
After this, I installed the High Sierra OS, and installed the Midas FW control panel via the SIP trick. So first disabling the SIP, install the Midas FW control panel, and don't forget to put it back on afterwards. And now here on High Sierra 10.13.3 it's working!