Yeah I agree and my own system doesn’t try to integrate. A lot of notes go straight into DEVONthink 3 via their sorter note taker. I love it in this version. I have several different ways I keep playing with of working text up. Including LaTeX, which I use less and less to be honest. If you try to use them all from within DEVONthink 3 I found I got into a real muddle. It wasn’t that you couldn’t do it as such if I remember. I just stopped trying though some time ago.
But actual composition and messing with text, eamail, longer form things I keep outside DEVONthink 3 until they are complete, then store them in an appropriate form there. Even archive some intermediate docs if I need to there. I don’t do that much I have found. I did integrate Ulysses sheets into DEVONthink 3 but I failed to see any point really in doing it and it confused me really.