I have a Steam Deck instead of a Switch for that reason. Doesn't stop me from admiring and envying the form factor, unfortunately.
I do think it would be fun to have a plugin and be able to control lights from the Steam Deck menus, too, though. Just haven't gotten around to trying.
Nobody has to have instructions on how to "hack" the Steam Deck because it's a computer and you just run whatever you want on it.
The instructions on how to crack open the immutable OS image are readily available from Valve but you probably won't need them since it's already got a lot of power even without that.
Indeed, a lot of folks liked the R4 cartridge for playing a wide DS title portfolio for free. However, piracy doesn't sustain a platform economically, and Nintendo is famously litigious.
In general, home brew people actually interested in building their own unique indie games often do not port to systems people have zero interest in supporting. Even publishing to Android/iOS would have less problems with <12% of users actually buying anything. =3
Proprietary closed hardware is not great for home brew projects. =)