Is there any way to tell CRUST to leave the wifi alone?

[wibble]

They aren't forbidden, they just need to use the appropriate lock. Ideally the app will do this so that the lock is only taken when necessary - while actually playing media for example - otherwise with a wrapper such as systemd-inhibit. This of course has implications for battery life. I don't know if the hardware supports specific wake triggers for network traffic - say wake on incoming packet on port 22 - which could allow greater power saving.