Yes, if you create a list and populate custom presets in the first 7 slots and then download it to the pedal, it will overwrite those presets.
If you’re concerned with erasing factory presets, I recommend backing up your pedal to a list on H9 Control. That way, you can always go back to it by simply reloading it into the pedal.
Another recommendation is to perhaps find a group of presets you don’t care for, say for example 90-99 and use those for your show.
What I like to do is create a preset list for my show and load it into the pedal. Let’s use your example, presets 1-7. Then, I purposely limit the pedal to only go from preset number 1 through 7, so if I try to go passed number 7, it automatically goes back to 1. You can do this in H9 Control. After my show, I load all 99 presets back into the pedal for studio work or whatever, and reset the limits back to 1 – 99.
