Shy, the horizontally opposed Lycoming / Continental is a crude old engine, just like all but the latest generation. Same technology as an old Brit motorbike!
There's nothing magic about them that requires different engine handling to those other types. Toggle mag switches would work perfectly well (and do in the Citabria and Cub, just two such horizontally-powered aeroplanes I have extensive experience of which use toggle switches). Why should a C150 or a PA28 be different?