I'm not a big keyboard nerd, but I had three of their keyboards, two of which were declared QMK.
As far as I remember, QMK software was extremely annoying from my own perspective, and the Keychron team was also dissatisfied with them (there was something about them being slow to add their keyboards to the app). I can say that I was able to customize my keyboards only after they released their own app.
So huge chance that your problem is caused by QMK, not Keychron.
Regarding app, i'm sure it can be made portable, maybe even via turning it into single file html.
As far as I remember, QMK software was extremely annoying from my own perspective, and the Keychron team was also dissatisfied with them (there was something about them being slow to add their keyboards to the app). I can say that I was able to customize my keyboards only after they released their own app.
So huge chance that your problem is caused by QMK, not Keychron.
Regarding app, i'm sure it can be made portable, maybe even via turning it into single file html.