Lock manually edited workouts

[TheBig-O]

I noticed that if you refresh a workout you have edited, the edits are removed in favor of the values from the original GPX. It appears that the notes do stay so I can leave breadcrumbs to get back to what I had edited, but having a checkbox to lock in the values would be awesome.
The main use case for this is when I have a workout on a treadmill. The GPX contains the time value but often does not provide the distance value. Once I add that value, I would like to have it stay if I accidentally hit refresh all or otherwise refresh the record.
Not sure how much trouble a capability like this would be, but having it would be great!
Thanks for your hard work on this!