[TheOtherCliff]

I've actually asked the same thing.  It's my understanding that it requires a different firmware at least, and maybe a new GCS depending on how the firmware is written.

So two ways:
- quick and dirty to make a Revo firmware that acts like an OpLink
  it may even have to announce itself on USB as OpLink depending on how the GCS is written
- add "OpLink emulation" to USB HID device function list in Hardware tab

I started looking at the quick and dirty firmware a couple weeks ago but got side tracked.  I don't know when I will get back to it... 

I ordered one of these for stock (USD $14.50 shipped) but it hasn't arrived yet.  At that price it I reserve judgement until I've tested it.
https://www.ebay.com/itm/OPLINK-MINI-CC3D-REVO-Universal-Transceiver-TX-RX-Module-Remote-PPM-input/121779927980

[sam028]

This might be a bit tricky for me to modify a Revo firmware but I'll take a look.
$16 from HK with shipping: https://hobbyking.com/en_us/openpilot-oplink-mini-ground-station-433-mhz.html . I'll go with HK for mine(s), I never had bad surprises with them.