switch/restore are not experimental in that sense, they're experimental in the sense that they're not guaranteed stable so don't rely on them for scripts or something (I occasionally tell myself I should adopt them and get them stabilized, but then don't do it)
It was experimental to allow the developers to tweak UI, including breaking backward compatibility if needed. But I left Git shortly after these were added. I guess nobody picked this up to finish the job (even by just removing the experimental status, since nothing has changed for years and I assume nobody complained about them).
