In Wikimaps Warper the "Edit tab" is only available for maps uploaded by myself. I think it should be also possible to edit maps from other users as well.
Folks - we are tracking tickets etc on GitHub currently
We use Phabricator for issues relating to the server / labs / WMF tech side of things but not for user bugs reporting.
We do of course welcome issues here too, but it could be better to post them to github to get proper attention from developers.
In the new year, as a result of the IEG Grant we will be addressing most of the bugs and adding new features too. https://meta.wikimedia.org/wiki/Grants:IEG/Wikimaps_Warper_2.0
copying to github and marking as resolved (It current expected behaviour and not a bug, and I'm not sure that this is a desired feature)