I switched over from my Ruckus APs to my new EnGenius APs last night. So far, so good. Used the same SSIDs and passphrases, and everything reconnected to the new APs fairly seamlessly (including my crapton of IoT devices).
I noticed that the ezMaster VM they provide supports HTTPS on the web UI, but (as far as I can find) doesn't actually give you a way to upload a custom cert. This is annoying, because a) you get that annoying browser warning about a self-signed cert when using HTTPS and b) Chrome won't auto-fill passwords on the login page.
Since I'm using Proxmox, I simply rebooted my ezmaster VM with a Ubuntu Live CD ISO, which auto-mounted the VM disk (plain old ext3 filesystem), and then replaced these files with new ones from the certificate authority on my OPNSense install:
/usr/share/ezmaster/conf/nginx.crt
/usr/share/ezmaster/conf/nginx.key
I stumbled upon this almost by accident, when I noticed that the backup file you can download from ezMaster is just a gzip file (despite the .bin extension) and, when extracted, I found a nginx.conf file, which conveniently had the paths to the cert and key files.
I could probably use the same trickery to set up an automatic redirect from HTTP to HTTPS as well...I'll give that a try tomorrow (I have a few other things behind Nginx reverse proxies that already do exactly that, so I can probably just copy the relevant sections out of their configs and be done).