Check out evil to use vim keybindings within emacs. If you want a battery-included experience, try Doom Emacs where enabling evil is a breeze.

If that’s something that matters to you, do know that Boox does not comply with the GPL licence.

There were some controversies due to the toxicity of Hpyrland’s community (namely its discord server). See this post for example

Edit: I should have read OP’s linked post first, which actually also refers to Drew’s post.