Not letting worker finish assignment if worker is not nearby assignment

**If a worker is not nearby a mission worker still can finish the mission. If you have let's say 500 worker in a project it won't be easy to track down which missions are correctly completed.*

It is not easy to track down a lot of workers. We have a workforce project fully integrated with many other arcgis platforms such as dashboard and collector. If a worker completes the mission without being there, all the data we collect becomes unusable.

**In order to complete the mission worker must be inside of the described radius around the assignment mission **

An implementation or if there is a way to make this happen or any alternative to consider.