Okay, there was a change several months ago which added the location tracking capability (ArcGIS Tracker License) to the Field Worker User Type. So there is no additional cost if you're already using Field Worker User Types.
The only thing you have to do is enable location tracking for your organization on the Organization Settings page - there's no cost for storage of the tracks though it's limited to 30 days in ArcGIS Online. The users just need to enable tracking when they open the app. There's also a new map setting that requires tracking so that tracks are recorded when the user opens the map, similar to Collector Classic.
I'm not saying your idea doesn't have value - we've heard it before but I believe all of your concerns are already addressed.