Hi Verminante, welcome to the RME user forum.
The integration ("remote control") of mic preamp into TM FX (the so called "Auxdevice" feature) is only supported for Octamic XTC, but the XTC is not being manufactured anymore.
Auxdevice support for the 12Mic is since longer on the TODO list, but much delayed due to Corona, Chip crisis, ...
There is no concrete date known, I would recommend not to wait for it.
Therefore, you should concentrate on what is possible.
The 12Mic would fit nicely into your setup as it has the same new preamps with 75 dB gain range (without PAD!).
You could use the new "MIDI Remote AVB" which supports the following mic preamps nicely: XTC, 12Mic, AVB tool.
It's a more compact and more worked out application to remote control mic preamps compared to remote management of 12Mic with a web browser (which would also be possible).
But then you need to also change your recording interface to UFX III, because "MIDI Remote AVB" needs MIDI, either physical or via MIDI over MADI. Since the 12Mic has no physical MIDI ports, you would need to use MADI for this to work.
So, you also need to upgrade the UFX II to UFX III if you want to operate the 12Mic with MIDI Remote AVB.
The only alternatives are currently for the 12Mic: via the (small) display or via LAN using a web browser.
Below, a screenshot of MIDI Remote AVB. I have an UFX+ and remote control Octamic XTC and 12Mic by using this tool.
I know, I know, costs … but I think, this would be the best solution.
BR Ramses - UFX III, 12Mic, XTC, ADI-2 Pro FS R BE, RayDAT, X10SRi-F, E5-1680v4, Win10Pro22H2, Cub14