There is no op-mode python wrapper script (along with the cli tag-node/bash completion stuff) for mtr, which is the pathway to enabling VRF functionality. Proposing to add it :)

'vrf': {
    'traceroute': 'sudo ip vrf exec {value} {command}',
    'type': '<vrf>',
    'help': 'Use specified VRF table',
    'helpfunction': vrf_list,
    'dflt': 'default'}

I'll get a pull-request together...