X-Wing Delta - Correct Control Surface Configuration

I’m in the process of creating a new design for a tailsitter x-wing style craft.
The idea is essentially two delta wings at 90 degrees to each other.

I understand this is theoretically possible due to the support for single-motor tail-sitter configuration, but I’m having difficulties understanding the correct configuration for the control surface.

It feels like the correct method would be one of the following:

  • Have a “flat” wing acts as elevon’s, and then a secondary which has a rudder input on both surfaces
  • Have “flat” be shaped like an “x” and have some form of elevon control on all the surfaces.

Thoughts? Is there a better configuration I’m missing?