What do you mean by "longevity"? Notes in Notable are plain markdown files, that's about as portable and long-lasting as it gets.

There's no encryption by default, but you could put your notes into an encrypted image, read more about this here [1]

I had never heard of Standard Notes, fortunately now I can say I have my note-taking needs covered so I've no interested whatsoever of making Notable a front-end for a third-party service. Perhaps we could add support for importing notes from Standard Notes though, if somebody wants to work on that.

[1] https://github.com/fabiospampinato/notable/blob/master/resou...