Never heard of it before. However:

End-to-end encryption keeps your notes secure. Our export and API keeps your notes accessible.

I’m not relying on any ‘export’ feature for my personal notes. If they aren’t using an open format I can access with other software, it’s a hard pass for me. For me, I want the data separate from the application, so I can choose my own sync provider and switch editor any time.

TL;DR If it doesn’t support plain markdown files, it’s not an option for me.