LarsR, I agree with your reasoning. Certainly, a “production ready” hypervisor should allow snapshots. However, the link to the Truenas tech talk that I posted above has two ixSystems employees talking extensively about changes to instances coming in Goldeye, but they say nothing about snapshots. So I’m not sure.
In fact, the only official comment that relates in any way to this issue that I found was in this thread: Instance volume lifecycle management? - #21 by DjP-iX.
There, an iXSystems representative posted a comment saying instances "is an experimental feature that will continue to develop throughout the 25.04 versions and into 25.10, to bring in some more of these usability features . . . "
Since people had been discussing snapshots, among other things, previously in the thread, it’s possible that snapshots are some of “these usability features” that were being referred to. But who knows.