I think all should be stable, but the last commit is at the most risk of having broken something. In my quick testing, it appears to be working the way I envisioned. Comments in the code for you.
Another idea: should a simple trigger + click (no selection necessary be used to make or break persistent measurements? That might make the current extra persistence nicer, because the hand won't have to do gymnastics over the keyboard to make them.
I think all should be stable, but the last commit is at the most risk of having broken something. In my quick testing, it appears to be working the way I envisioned. Comments in the code for you.
Another idea: should a simple trigger + click (no selection necessary be used to make or break persistent measurements? That might make the current extra persistence nicer, because the hand won't have to do gymnastics over the keyboard to make them.
@typesupply