In Apple Configurator 2, there is an option to customise the “Trust” of a Wi-Fi configuration. This allows connecting to an enterprise network (in my case TTLS+PAP) without getting the “Untrusted Certificate” pop-up on iOS.
It would be great to be able to set these fields in the SimpleMDM UI too!
(I actually spent a few days searching why I was getting this pop-up on iOS, and not on macOS; turns out on macOS having the certificate installed in the keychain seems to be enough, but not on macOS…)