Thanks Carl.  I think I was wrong about the icon.  I did a quick search for both "substitution icon" and "reload icon".  They are similar with the reload icon having one arrowhead instead of two.  So probably not a big issue.  Maybe try doing the word swap with the icon behind it.  Similar to this but more compact so it would fit.

I would also add that it should also remember the bar weight per location profile in addition to the exercise. My home bar is different than my gym bar and my home EZ-curl bar is different than my gym EZ-curl bar.

Thank you Nick. I had not found that feature before. That is exactly what I was looking for. Now that I can look ahead, I can see that I made some substitutions that do not make sense. I also now understand what the circle-looking icon is next to the exercise name. It looked like a reload icon, not a substitution icon.