Would you suggest using a different name for a MHFA, maybe a MH champion, to encompass the wider pro-active role?

This may be a good idea – whatever name they are given, it is essential that MHFAs are empowered to take a proactive approach to organisational mental health and that they have the bandwidth to be able to discharge their responsibilities.  The name should reflect the culture of the organisation, the key aspect is awareness and accessibility – identifying a name for your company that supports this is key.