I am using Planck keyboard from OLKB, powered with QMK firmware.
What I tried to do today was assigning F13-F24 and numberpad keys on one of the layer, on alpha keys (or former place of alpha keys).
So even when Plover is on, Plover only hooks those seemingly useless keys, and pass-through all other keys present on normal keyboard.
AFAIK standard steno needs only 23 scancodes, which are already outnumbered by F13-F24 and numpad keys.
I though in this way one do not have to turn Plover on and off frequently to type in some not-Plover-friendly keys, because Plover only use already unused keys.
But Plover keyboard settings does not have option for those keys.
I would really like the feature, since I have to type Hangul(Korean) much more than English, so turning Plover on and off turned out to be tiresome.
Or, soon I will get another keyboard dedicated for Plover, then I will be able to freely use two keyboard alternatively, or even simultaneously!