At least on the keychrons i've got, you can absolutely configure layout changes via key combination, and that slide switch is just an input like every button is an input.

I've got 2 that both run QMK firmware, so maybe the non-QMK ones can't do that, but at least some can.

Have been using one of their keyboards for two years switching between windows and macos and that key was not the one that wore out first. Plus on most keyboards you could configure the layout switch with qmk anyways.