This is not a nano alternative, it follows the vim paradigm of having a command mode that nano does not have (for good reasons). It's more of a merge between vim and nano if anything, breaking the core intention behind nano.

If you ask me, nano has a niche of a super simple terminal editor that anyone can look at for the very first time and instantly figure out, with very few pitfalls or ways to mess up. The more features you add, the more modes and options, the easier it is for newcomers to press a key combo that puts them in a state only intended for power users that they won't be able to get out of without googling.