Switching between data entry formats


if I remember correctly, it used to be possible to switch between default, section, and custom data entry form while in the data entry app. I can't see that this is possible now. Is there a way to do this, without affecting all users? Or better, to switch between two custom forms?

Our case is a rather complicated custom (official) form, where we want to explore other ways of displaying this for users. The point is that we need to keep the official form, and only test alternative layouts for specific users. An alternative could be to make another data set with the same data elements, but this is messy. Any thoughts, or similar experiences?