The user Program list is for storing Programs, not Presets. Presets are stored in the Library, as mentioned in your manual link. I don’t have my H90 plugged into my PC at the moment so can’t check, but am pretty sure there’s a way to save the Presets at the top of each individual Preset (A & B) section in H90 Control, and you can also access the Library too. Probably worth reading this section of the manual:
https://cdn.eventideaudio.com/manuals/h90/1.11.4/content/h90-control/index.html
