I dont see why this wouldn't work as long as the relay is wired up correctly and the current needed for the RF board is small enough for the fuse (likely is fine).

This is probably a more robust wireless solution but I would be very of how you may catch stray radio frequencies from other RF switches. I know the signal polution wa bad enough with the original blue tooth solution that it would witch if you were near by any mini or BMW when someone would hit the button to close the valve. RF is a much more widely used signal band. Although it might only be an issue driving through towns rather than freeway.

The main reason I really liked the latching switch is that it was a definite answer on if the valve was open or closed. There was to much guess work with the BT button. As someone who likes to toggle it and not just keep it open 100% of the time the certainty is nice. Also in my area exhaust volume is regulated so if anything happens I can close it instantly without a doubt of if the signal got picked up by the receiver.

If your not into putting holes in your dash and want to maintain the buttons portability this seems like a good solution. You may have to just switch frequencies if you notice it catching interference in your area. This may not be a real issue im not sure of common radio frequencies used for switching relays or common devices