I’d love to see an NTP client option as has been said before.
There have been counter-arguments to this that NTP is only for big corporate networks but the worlds of AV and IT are merging, certainly in a technology sense.
Not at all suggesting that show networks be hooked up to the IT ones in facilities where that is possible, I still believe keeping them separate or at minimum firewalled is a sensible thing to do most of the time.
There are easy NTP server options for an isolated LAN though.
You can knock up an NTP server on a Raspberry Pi these days for cheap and stick that on your show network to keep everything synced (assuming all devices have an NTP client).
If you want to go the whole hog you can easily add a GPS reciever to the Pi and sync accurate time from the GPS satellites.