Technically there is/was no need to edit the widget itself, the event "route code" is defined at module admin area and it works both for API endpoint and Event Widget.
No need to edit/alter line 16 of the widget controller as it simply reads the above definition.
Technically yes, that map is powered by API calls, Leaflet (map) + Rivet (data on the map, JavaScript) and you can replicate it easily anywhere with proper coding. This was talked several times in Discord with some other possible solutions, if you are a member you can check those old suggestions too
Good luck