The above, coupled with a job that leaves 2 hours in a day free, cause me to read Occultic;Nine VN for 1-2 hours per week - a snail speed. Can't finish a route I'm reading in more than a month I think

Haven't figured this out myself too, however unless there is some new feature in a newer API that you need, do you need to update minimum API?
For app development I'm using 8 as a minimum too, so I'm not the one to advocate for higher. But 10 doesn't sound too crazy, although it's only 5 years old

Still, changing layouts is a minefield of issues: from some things working only with Qwerty layout like boot, bios, and first login passwords; to having shortcuts change from colemak to qwerty layout when you switch from english colemak to other languages

I believe it was more worthy and easier for me to switch to Colemak DH on a standard keyboard than to use an ortho keyboard (with colemak)

As for my custom ortholinear keyboard (got it at the same time as Colemak switch), I still haven't found a usable usage for it, and I can't type in qwerty on it as well as colemak