Non moving / radius-limited challenge: proof of concept

I've seen people suggesting an option to limit movement, either with a distance limite ( like a radius around the starting location) or with no movement at all.

User PistachioCaramel on Reddit took a look and created an example of limited range gamemode: https://jsfiddle.net/rushmoom/vr6zj2ns/ 

You can set a starting location and a maximal distance (radius), and when the player tries to go above the range he will be teleported back to the latest panorama, blocking him from escaping. This is not perfect as setting a very low distance may result into bugs but again, it's not a finished product, just a proof of concept to show it is indeed possible to make it.

This would be a very nice addition along with the possibility to block all movements for non-moving challenges.

I know you - Geoguessr devs - are limited in free time but still though it could be interesting for you to check this and maybe implement this in the future a a game mode where players can set a distance limit (0 being non moving at all, disabling the Streetview arrows display in the same process).

Thanks to PistachioCaramel for making this.