Manual chapter 15 tells you that the current driver supports up to three cards.
What do you mean by expanding your system with UFX+ ?
Do you mean
A) 3 x RayDAT and 1 x UFX+ or
B) do you want to replace the 3 RayDATs with one UFX+ ?
RayDAT and UFX+ use different ASIO driver, so your DAW can either load RayDAT or UFX+ ASIO driver, not both.
So you have by this either access to the UFX+ or to the three RayDATs
The Limitation of using 3x RayDAT is, that you can only route between channels inside of one RayDAT card.
I don't know what port types you require and how many of them.
The RayDAT is a 72 channel interface, 3x 72 = 216 channels, fully digital
The RayDAT has separated AES and SPDIF channels, 2x MIDI
The UFX+ is a 188 channel interface, partially analog, partially digital, with preamps, instr. inputs etc.
ADAT2 and AES channel are not really separated but kind of bridged.
If you need a lot of ADAT ports, then you need to buy ADI-648 additionally and connect it to the MADI bus.
But then the MADI bus is full.
An alternative to that would be to get a MADIface XT or the HDSPe MADI FX card.
The latter is really nice, I wrote this article about the product:
https://www.tonstudio-forum.de/blog/ind … Pro-FS-BE/
The Full Review in this PDF:
https://www.tonstudio-forum.de/index.ph … l-v1-1-pdf
The UFX+ is a fantastic device, if the type of channels are fine for you, take it, you can't do anything wrong with it.
MADI gives you a nice flexibility and you have DURec.
The HDSPe MADI FX is nice if you need multiple MADI busses. Its the only card with a full implementation of FX chip and it has a very unique driver which uses only system resources for those audio channels that are active. More details in the article above.
Also a very nice combination is UFX+ and Octamic XTC,.
Because the XTC can be configured in TM FX as so called AUX device, its then like a channel strip in TM FX.
By this you can remote control nearly all functions of the XTC and store the settings digitally in snapshots.
The XTCs Mic inputs can also be used as line level inputs (A/D converter).
It can also be used as format converter between ADAT, AES, MADI.
And it supports class compliant mode to be used as recording interface for an iPAD. Lots of features !
More information in these two blog articles that I wrote:
https://www.tonstudio-forum.de/blog/ind … 8-RME-UFX/
https://www.tonstudio-forum.de/blog/ind … Cber-MADI/
You can use the UFX+ also very nicely with USB3. If you choose a 3x shielded quality USB3 cable from Lindy, then you can use even 5m long USB3 cable, which gives you much flexibility to place PC / recording interface.
One of the uniq features of the UFX+ Thunderbolt driver is that it supports the pitch function, which is not possible with the MADIface driver and its USB transfer modes.
X10SRi-F, Win10 Pro 1909, Cubase, UFX+, Octamic XTC, ADI-2 Pro FS BE/R BE, RayDAT, ARC USB