M4300-12x12f not honoring copy command source interface

[DonnyRoss]

I have an M4300-12x12f located in a remote subnet.

When I try to copy the config to an ftp server with copy nvram:startupconfig ftp://1.2.3.4/path/file.cfg 

The switch uses the source IP address from the vlan IP address associated with its default upstream route, not the defined management vlan IP address.

Maybe this makes some logical sense, but when I append "source vlan 123" (same vlan as defined management vlan) it ignores this and still uses the vlan IP address associated with the default upstream route.

My workaround for this has been inserting a route for these routing vlan stub networks, but that's messy as there are many /29s associated with them and they are not easy to summarize with a supernet route.

Is there any way to make copy commands use the defined management interface?