There is nothing that would prevent the VOXL Flight Deck or any of MODAL AI's kit from being used in a fixed wing configuration. The underlying autopilot, PX4 can be configured to fly a fixed wing aircraft. The software on the VOXL "brain" is tuned for quadcopters and will fly out of the box but with adjustments I'm sure it can be done.
Someone from ModalAI can chime in, but it would not surprise me if other customers are already flying Modal kit on a variety of other platforms from ground, to sea, and other air configurations.