AOC VFR?
No problem with flying VFR with AOC aircraft, provided of course that it is permited and approved in your OM-A.
Also, despite of most likely flying with FMS, you better have VFR charts onboard.
Otherwise not legal.
The ash thing is then altogether another thing. If there is ash, don't fly. If not, go ahead.
We might be facing this for many many weeks in a way or other, so I do not think that grounding the fleet will be the option.
Cheers!