Map zooming is bound to - and + on keyboard, however there is no way to rebind them and they are not listed in the settings. Additionally, if anything else is bound to plus or minus (this happened when I bound "toggle HUD" to minus), the map is altogether no longer possible to zoom out.
#Map zoom/unzoom has no listed input binding
ember python
ember python
Restarting the game rebinds - and + to zoom in and zoom out.