The only difference in normal usage is that you eventually reach the threshold to be shown more difficult units.
Generally, this is the biggest barrier for me when trying out stuff - there are repos with explanations, but nothing to show how it actually looks or works.
Please add at least sample screenshot of your command line! :D
TaskWarrior is a good sample - it has a page that shows one workflow with commands, so you instantly feel like you know how to use it. If they just said "this is a todo app" etc, I don't think I would have tried it. I've also tried to convey what my app looks like exactly with actual screenshots - https://github.com/CatalanCabbage/the-wall
Or maybe it's just me being obsessed over this stuff.
Anyway, looking forward to try your app! I've wanted something similar for a while. Right now I use a spreadsheet for spaced repetition (with columns for difficulty and time)