I don't use the Honey Select engine for Harem Hotel. I take pictures of the Honey Select engine and put them into Renpy to create the game. VR support wouldn't really work with pictures, and will probably never be implemented in Renpy, as that is a visual novel engine, haha, sorry.
Someone did a demo of how to make Renpy produce 3D SBS images with depth - see https://lemmasoft.renai.us/forums/viewtopic.php?t=25178.
Actually implementing a VR version of Harem Hotel may prove to be far too much work to be practical, but it's not actually impossible (at least not down to the limitations of .Renpy)