Hey Wouter,
The FX send busses are purely for routing, and have no processing (though of course returns have PEQ), but what you’re wanting to do here isn’t too rare, and is a great technique!
It’s possible to accomplish with the available SQ architecture and processing too.
You just need to feed the reverb FX unit from an Aux (as a Mix->Return), then you can make use of all the mix processing (including compressor) pre-FX.
Hope this helps!
Cheers,
Keith.