A quick investigation on my UDM Pro showed that I could enter the unifi-os container, apt install software packages, and make changes which persist across reboots. It would appear that all changes within the container are persistent via an overlay for / which goes to persistent storage on the host. Sep 05, 2019 · Since Ubiquiti has stopped updating UniFi Video, we’ve all been waiting for a bigger move on the UniFi Protect front so that is properly scalable (unlike the single-drive Cloud Key Gen2 Plus). The UNAS 4 is likely that solution in combination with the UDM Pro, which is currently in beta with the Early Access program.
It's actually only a stable release for the UDM Pro. It's still considered beta for the UDM Base so it will not show up as an update in the GUI. You'd need to update from the command line interface but you also need to remember that it is a beta firmware for the UDM Base. level 2
Don't be surprised if your switch is unavailable for 5-10+ minutes as 4.0.3+ also updates the PoE firmware to improve PD compatibility. UIS-8-450W upgrading from 4.0.33 and earlier will have their PoE firmware upgraded automatically to improve PD compatibility.