Pi 4 as thin client for Ubuntu dual monitor

[Bernecky]

I want to put my noisy development boxes (Ubuntu 18.04) far from my lab, and use
a Pi 4 as a dual-monitor thin client to get to them. [I have no interest in Windows, btw.]
At present, the development boxes each have a pair of 1920x1080 HDMI-connected monitors,
plus your usual mouse, keyboard, speakers/microphone. I want to mirror the development system
desktop environments on the Pi 4, so I have the Pi 4 connected to the monitors via the HDMI ports.
I don't ssh can do the job, but maybe I am missing something.

The Pi 4 boots properly and uses both monitors correctly, IMO, from the get-go. I.e., mouse scrolls across both
screens, resolution is correct, etc.

I have tried several "thin client" apps, but none of them give me the same environment
as native support. Support for dual monitors is absent in all of them, and some
have various unpleasant things about their behavior.

I would prefer an open-source solution to this, but if need be, I am willing to purchase
software that works more or less out of the box.

Suggestions welcome!

Thanks,
Robert

[DougieLawson]

You can use ssh from an lxterminal. You can use VNC. You can even do Xwindows tunnelled over ssh.

What more do you need?

[Bernecky]

I have used "ssh -X ..." for ages, but that is not what I want: ssh gives me an xterm.
lxterminal seems to be about the same as xconsole, xterm, etc.

However, I do NOT want an xterm session on the Pi 4. I DO want the entire remote system
desktop, with task bar widgets, clock, etc. on the Pi4.
AND, I want it to support multiple monitors (on the Pi 4) in exactly the same way that Ubuntu KDE-plasma and
the Pi 4 support them, natively, out of the box.

x2goclient appears to be getting close, in that it works (sort of) for one
display/monitor (1920x1080). In order to get there, I had to:

install 75dpi and 100dpi xorg fonts
and
set x2goclient session preferences "Input/Output" to use:
"custom" (with 1920x1080)
"set display DPI" 75.
session type KDE (although the remote system is using KDE-plasma)

This gives me a full screen from the remote desktop, except that
the widgets and task bar do not appear.. Hence, this is not adequate.

Setting "xinerama" does not appear to change anything.

I tried vncserver a while back, but it did not seem to work any better than x2go.

Thanks,
Robert