It has been a while since I updated this.  I played around with a few
 Linux distros that should have worked on the Surface Pro 3, but I kept 
coming back to Mint Cinnamon because it had two things that worked 
pretty well out of the box.
A good deal of this experimenting involved some tiny USB sticks, 
well, more like USB ‘Buttons’ of various capacities from 64GB to 256GB. 
 The focus was on creating ‘Persistent’ Live Bootable USB drives, so I 
could properly test each distro and save my work between sessions 
including enything I had modified.
Both Surface Pros had Windows already installed, the 8/64GB Surface 
Pro 3 had WIndows 10, and the 8/256GB Surface Pro 3 was running Windows 
11 Pro, so I liked the Persistent Live thing because I could easily swap
 between Tablets and compare the performance of the different RAM in the
 tablets running each Distribution.
Originally I liked Kubuntu for the way it just felt and looked nice 
on the Surface Pro.  The big annoyances were the crappy On-Screen 
keyboard and the fact that if I disconnected the Keyboard/Cover to use 
the tablet standalone, I had to go in manually and select the orientatin
 of the screen every time I wanted to swap from Portrait to landscape or
 back.
That function was enabled by default in Mint Cinnamon.
I also ran a few other distros on the Surface with varying results, but it kept coming down to Cinnamon or Plasma.
When my mind was almost made up to stick with Cinnamon because of the
 screen rotation, Neon had just moved from Alpha to beta, and I had 
downloaded a copy.  On a whim I tried Neon 6 Beta on the Surface Pro, 
about when Neon was transitioning from Plasma 5.27 into Plasma 6. 
Everything
 was running beautifully and I liked the newer Plasma style better than 
Kubuntu’s.  The trouble was – that stupid lack of autorotate of the 
screen was still a pain.
Now, one of the beautiful things about Beta testing is that the whole
 point of the testing is to try to run a new Distro or App on as many 
devices as possible.  So I filed a bug report about it.  In the meantime
 I had found a way to make the screen rotate automatically, so while I 
was at it, I sent the details about how I was making it happen and asked
 if this could be implemented before Plasma 5.27 actually released as 
Plasma 6.
One other beauty of having a go at testing a Beta is that 
some developers actually read requests and suggestions.  Within a few 
days I had an acknowledgement, and in the next Beta it was operational.
That experience sort of sealed the rest of the search for a Linux Surface Tablet OS.   
I’ve
 been using Neon 6 since that time and it has got better and better.  It
 is one of the best discoveries I’ve ever made in more than 20 years of 
using Linux as my daily Operating System.
 
(Neon 6.2.2 on a Surface Pro 3 with 8/256GB at October 26 2024)
 Now there is only a single hurdle.  Most Linux distros are moving from X11 display for graphics, to Wayland.
One of my major uses for a Linux Tablet is as a terminal into my various other Linux computers that run on my home network.
Also,
 as I think I’ver written before, I use VNC – Virtual Network Computing,
 rather than traditional networking.  That means I can basically ‘Remote
 Control’ various other computers from my Surface Tablet.  I have a 
single %% inch LED Monitor, with several computers connected to it using
 HDMI.  
All can be controlled using a single Mouse and Keyboard without having to change or switch anything.
I use the Virtual Desktop function built into Linux to simply open 
each remote computer’s desktop in whichever other computer, in this 
case, the Surface pro tablet.
I can also remote into any other computer from my main one viewin them in the same way, on a Virtual Desktop.
Mouse
 and Keyboard control move from one to another automatically as soon as I
 move the mouse cursor into the Window of the other machine on its 
Virtual Desktop.  It sounds a lot more complicated than it is.
And the problem?  
I use an App called NoMachine to run my VNC.  NoMachine does NOT play nice with Wayland just yet.
For
 now I gan easily get around that by simply log in each machine into a 
Plasma (X11) session, but eventually if Neon drops X11 support I’l be 
stuffed.  For now KDE has plans to keep supporting X11 for legacy 
systems.
One last thing.  I was so pleased with the way Neon 6 / Plasma 6 
works on the 8/256GB Surface Pro 3 that I wiped Windows 11 (which I was 
updating, but never using) and installed Neon 6 to the internal NVMe.