Hi,
I often find myself in the need for upgrading to the latest rolling release (e.g. to mitigate bugs or add new features). I often have setups where management (ssh, ntp) is in a VRF and the default VRF has no internet access. It would be very useful to be able to do "add system image http://10.1.2.3/vyos-rolling-xyz.iso vrf management" (or maybe place the vrf before the URL? I don't have a stron opinion on where to place it).
I think this should be quite easy to implement since it shouldn't take much more than adding something like "ip vrf exec {{ vrf }}" infront of the curl/wget.