Allow unlimited time for custom Movement + ability to add notes

Right now it's not possible to set Reps for a custom Movement. I would like to add a movement to my training (for example a Body Weight Exercise) and define how many repitions should be done. This could be added as a note that could be shown in the UI. It's cumbersome to add a timer to each exercise that isn't really used as I don't know how long the exercise will take me and then look up how many repititions I had planned for this exercise on my phone / or a piece of paper.