I disagree that live events are more complex with regards to clocking. On the contrary, it's way easier. The system is fixed at either 96 kHz (most of the time) or 48 kHz (in "budget" environments). Most "96 kHz units" also have sampling rate converters, so they will happily take whatever they get. The only critical point is setting the clock master.
As the live sector has been and is the driving force behind Milan/AVB, this has been resolved in a fairly easy way:
Hive, for example, offers a media clock setup where you assign all units to a media clock domain and select the master device. As long as all units are Milan complient, i.e. have dedicated CRF in- and outputs this really just works.
However, in the studio, where you are trying to avoid sampling rate conversion and have to deal with 44.1 kHz and 48 kHz and multiples thereof up until 192 kHz, things are more complicated.
Not due to the fact that every device's clock domain has to be set to the correct sampling rate - that's the easy part.
The hard part is that for all stream in- and outputs on every device the stream format has to be set up according to the sampling rate. This is done by the RME AVB Controller (and our device's web interfaces), but only per device.
Hive, that is able to control multiple devices as described above, doesn't set stream formats along with the rate. It doesn't know if a device supports sampling rate conversion or not, and if so if the user wants conversion, so it just doesn't touch formats at all...
We already discussed this issue with Hive's main developer, so this might improve in the future.
As for "simply following one device": As Matthias already said, reconfiguration is complicated. All streams have to be stopped, clock domain and stream formats have to be set up, streams have to be restarted again. As AVB uses stream reservation, the reserved bandwidth has to be changed along with the format, which takes up to 20 s in a legacy AVB network. It's not just "simply toggle a bit to set another rate", like with MADI or ADAT.
Btw, the same is true for other Networks like Dante, where you have to select each device in the Dante controller, go to the Device Settings tab and manually change the rate.
To conclude with something positive: It's not impossible to do it, but it's not just an extension to existing devices or software. Ideally there would be a specialized AVDECC controller for studio environments that is somehow tied to the DAW, but clearly gives feedback to the user what just happens and, if in doubt, let the user decide what to do. And as AVB and Milan are open standards/specifications, this piece of software doesn't necessarily have to come from device or DAW vendors. But of course it might, see Aneman in the AES67 world for example.