Can we use 4 TM MFD's in the Viper?

So I have 4 Thrustmaster MFD's. In the hornet I have assigned 3 of my TM MFD to respectively the left, right MFD and the AMPCD. I assigned the buttons of my fourth TM MFD to UFC functions. And that works perfectly. I would like to do the same in the viper: use 2 TM MDF for the left and right MFD and use the buttons of the third and fourth TM MFD for other functions (IPC, ...). Problem is that I'm not able to assign functions to my 3rd and 4th TM MFD. Am I missing something, is there a workaround, will it be available later in early access, ...

Any help is much appreciated!