OK time to put this to the test, I ended up setting my $VISUAL env
{-here-} variable, so that jenny can launch neovim instead of plain old vi like
{-here-} it is instructed in the code. But as you can see, I still get these
{-here-} wired new lines every ~70th character (marked them with {-here-})

I might have found the actual source of my problem.

Jenny uses an .eml file when composing a twt …
and vim kinda auto formats it and inserts in those line breaks every ~70 character.

Then, I stumbled upon this link where Where someone reports that saving a .eml into a .txt might… corrupt the data?

… Or, maybe (most likely) I don’t know what I’m talking
about.

Anyway, let’s get … Twtn’? Twtxting? Tw… /me will shut up! 😶