There a many misunderstandings about expimentals. I'm not the expert either, but I am often amazed by the owners that think they can legally experiment with changes to an experimental glider.

An experimental glider has to be maintained per its operating limitations instructions, which usually says per manufacturers instructions.

Experimental homebuilt is a different animal than experimental aircraft that are manufactured.

I have a PIK 20 with an experimental certificated, and I do an annual for the owner of a standard certificated PIK 20.
As mentioned before, I depends on how it was certified when imported.