I've seen a fair number of folks in the mechanical keyboard community (admittedly rather small already) that customize their switches. For example, a common mod for mechanical switches is to replace the springs in the switch housing, which affects how much force is required to depress the switch. Others replace the stem, which is the colored part of the switch, changing its feel (tactile vs linear, smooth vs course).

Given that, would you consider someone building their own switch as someone who's created a custom switch from these components? e.g. I've read of folks putting Zealios stems in Gateron housings with 80g+ springs to create their ideal switch type.

As far as I know, most keyboard manufacturers don't manufacture their own switches, yet it's fairly uncontroversial to describe them as "keyboard manufacturers."

I've built small keypads with aluminium foil and sheets of plastic; extremely silent but not very tactile.