A couple more comments.
Documentation
The docs are slightly out of date for line/polygon as the vertices aren't shown currently (at least for polygon, I haven't tested lines recently)
Line and polygon choices are represented by red lines connecting small white circles at each vertex.
+/- zoom buttons
I know @seewhy wants +/- buttons to zoom when you can't two finger pinch, as did @Alain_Benard. They would be handy in cold/wet/dirty environments when gloves are worn. These were removed from OSM early this year though (due to OSM bug creating points when using them?) so I'm not sure they're coming back.
Indicate selected polygon/line
A selected geopoint enlarges to indicate the selected item, but a selected polygon doesn't change in appearance at all apart from a slight map zoom and a pan to centre it. If there are multiple polygons in the area it's not clear to the user which one has been selected. I don't have a great suggestion as to what to change to indicate this - show vertices / invert colouring / remove fill / change outline weight or style / flash element? Show vertices might be the simplest as a fixed colour change may clash with styling colour. Changing the stroke might not be feasible, especially as Mapbox doesn't obey it currently.