Regarding Razer Core X I use it interchangeably with HP G2 Dock. It has nVidia 2080 Ti onboard.
Actually that is my new toy and I barely started to use it. Ubuntu 19.04 and 19.10 had serious problems to recognize it correctly: I had a number of issues related to non-signed “something” and invalid certificates in
dmesg. Cannot recall it now but the clue is it was not working with 19.xx at all even if recognised by the system. I didn’t test it with 18.04, but I’ve read people state it works.
Under 20.04 it works OK as directly connected. Yoga has an only single Thunderbolt port, I was hoping to connect it as daisy chain to the HP G2 dock (yes it is possible) but the throughput of the G2 dock is not enough to handle PCI-X monster GPU and you cannot use it this way. Even if they seem to wake up, the message in
[ 898.469440] pci 0000:10:00.0: 8.000 Gb/s available PCIe bandwidth, limited by 2.5 GT/s x4 link at 0000:08:01.0 (capable of 31.504 Gb/s with 8 GT/s x4 link)
So I assume this is a physical limitation to connect both to a single Thunderbolt port. Thus I only have a choice to connect HP G2 or RazerX, not both.
Regarding Razer itself, I made it to install proprietary Nvidia drivers and run an external monitor. I believe it is possible to use more than one but I was struggling to run notebook’s display and external monitor parallel as they use separate GPUs (internal is integrated Intel, external is Nvidia) and you need to run complex, double X11 configuration. Didn’t have time to make deep research here, however, I do not really need one, as all I need is to use Nvidia as computing for deep learning that works well without the need to use it as a display.
In such configuration, I use integrated GPU to render Ubuntu and Nvidia is just for computing, not for display. Anyway, the external monitor (if connected) remains blank with … mouse cursor on it ;-). Pretty funny, because it seems like extended desktop works but there is no x-windows server active, to render a single thing. Even if you move a window to it, it just disappears. I read somewhere there is a solution to this problem, didn’t try it yet as not in my priority list.
Just to read your question right: what do you mean by “multiple monitors”? You mean Notebook + external or more than one external connected to Nvidia?