@jswoveland, not sure if this helps but I’ve been messing with leaflet, Mapillary, and codepen a bit and figured I’d put together a basic demo highlighting the aspects I originally was struggling with as well.
https://codepen.io/lewin76/pen/oggmKQW
In the demo, double click the map or paste in a lat/lng string, set the distance for your bounding box to constrain your results, and hit the button to kick of a search.
The task of initializing a map and setting a point of interest should be as simple as it is with leaflet or any other map, where you supply some coordinates, and the map takes care of the implementation. It takes a lot more work here, and it’s unclear why the api puts the burden on the user but hopefully the codepen provides some insight into what factors affect the lookup, what’s needed for a minimal query, and get you a bit closer to your goals.
If nothing else, it’s a small demo that might help the next guy…