FYI, it looks like OS 2.2 just doesn't have mDNS/avahi enabled. I've tried it on the M525 and an M505. I was on a different network so I was trying to find the IP address with avahi, and then resorted straight to flashing it when I couldn't find it.
It looks like IDE 2.1.3 doesn't support the M525. I've got a solution with two existing M505s I wanted to add it to but it doesn't even show up as an option in the manual device list. Do I have to upgrade my solution to IDE 2.2.0 to add the M525? It looks like this will require me to upgrade the OS on the M505s (from 1.9), correct?