My only problem with both designs in your images is the colors. It’s a pretty standard part of UI design (in real life and on computers) that “red means cancel” and “green means continue.” Apple using blue is no big deal and I’m 90% sure they just use a user chosen “highlight color.” (Maybe Gnome as well?) But cancel or delete or similar things should probably be red or another color that signals “Stop.”
I’ve always thought Bootstrap, the web design library, has a good set of base colors. Red means danger. Light blue means info. Green means yes or success. Yellow means warning. Other buttons are a darker blue — basically the highlight color. (Not saying they chose the best version of those colors. Just that the general idea is consistency and what users most naturally expect.)
I don’t have Linux on a tablet right now but my first thought was that you might want to check into what Steam Deck users are doing with “Desktop Mode.” It has a touchscreen and virtual keyboard so it’s essentially a tablet-like experience (though it has touchpads and a few buttons, obviously, and isn’t a tablet). It runs KDE by default, which I’m not as familiar with as Gnome, but it might have more users than any other GNU/Linux touchscreen product.
Last time I had a Linux tablet, there were also some Firefox/Chrome/Gnome extensions that made it more touch-friendly. Like instead of selecting text, one finger swipe scrolled, two-fingers zoomed in, etc. like a typical tablet. Not sure if that’s still an issue. But if you do run into an issue, it might already be solved by an extension.
Hopefully, someone has more up-to-date advice. The tablet I had (and probably still have in a drawer somewhere) was an experimental Ubuntu Touch device and there’s been huge strides since then.