I have a Dell Inspiron 7306 (2-in-1), that comes with both a touchscreen and dockable pen. I run Arch Linux (btw, sorry I had to) on it and Obsidian works just fine in the traditional keyboard and trackpad mode.
When using the touchscreen, touchscreen-style scrolling works, but that’s about the end of touchscreen support so far as I can tell.
On mobile, you can, for example, pinch to zoom on the graph view. On PC no such functionality exists. And, like the related feature link I embedded, I don’t believe you can touch-drag resize panes either.
Also, this is probably an electron issue in general, since discord/vivaldi does this too, but I cannot touch-drag/resize the window on Linux. I use Wayland with GNOME 4x, so I do have really great native touch-support. Other windows that are not Electron work just fine for touch-drag.
Improve/add touchscreen support where possible. The electron window dragging bit might be out of your reach and I completely understand that.
Just use obsidian in the traditional laptop mode. Works like a breeze, love it.
Again, scrolling works on touch screen just fine.