I haven’t been doing too much driving since I bought my RL360c two months ago, and I don’t recall it falsing to any CX-5s as I think I have encountered several. The BSM filtering seems to be very good on the RL360c.
If anyone wanted to do further bench testing, I located the wiring diagram and pinout for the radar heads. I'm assuming once power is applied the horns go live, but I could be mistaken. Probably a cheaper part at a junk yard, plenty of wrecked 2017+ CX5 is imagine with their popularity. The left one has the CAN lines to the computer, so I'd probably pick that if you're only gonna grab a single side.