It would be nice to be able to invite to one's map those who may have similar interests but who are not on your followed list or known to you. For example to invite all those who have participated in 'environment' maps. This ties in a bit with giving users a list of maps to subscribe to.

Perhaps on registering, users could be given the option to register interest in - at least initially - broad categories of interest eg environment, politics, health, education etc and would then be directed to a list of existing maps that include those issues (there would have to be some tagging of maps rather than relying on the word appearing somewhere in an issue or position etc)

This would enable a map user to identify others who may either be interested in contributing to one's map, or who may have knowledge/experience to something that is relevant to a map user's non-mapping work life.