Hi Ian
I run Tess on my Surface Pro 4. In a Remote Desktop session from a terminal server, not directly, but adjusting the resolution to be effective was similarly problematic.
Mostly, I think, because the Surface has such a high native resolution, and old-fashioned database app development tools like Powerbuilder (which Tess is mostly built in) build screens that aren't very adaptive - they just use the pixels as they come, and the real pixels on the Surface screen are tiny little things.
There are two other display factors that you can tweak to get a better result.
Firstly, you can change the apparent resolution of the screen - I have mine set to 1920x1200 (the common High-Def 16:10 screen resolution) rather than the Surface's native 2048x1536.
And then you can set a custom scale factor - I have mine set to 200%, instead of the 150% (IIRC) that the Surface was set to originally. Thats all under Settings/System/Display/Advanced display settings. The Surface really doesn't want you to change that setting - it buries it way down in the Settings, and says
But it does help, and you can play with how those two settings interact until you come up with something that works for you.
That works for Tess, but of course it means that you don't get the full benefit of the high resolution for other apps that are more adaptable. You can switch back and forth, but you need to do a reboot for some of that to take effect, so that's a bit clunky. I'm still fiddling with the settings - there's no perfect setup, but this setup gives me a reasonable compromise so far.
Ken
Hmmm. That warning text doesn't display properly, in spite of the promise offered by this new html-ey text edit box that the forums have suddenly developed....
What it says is "If neither of these makes the changes you want, you can set a custom scaling level (not recommended). Setting custom levels can lead to unexpected behaviour on some displays"