When the envelopes are linked to the clip duration, you can see the notes
and it's very easy to see where the envelopes are going to hit the notes, but when you unlink them, the notes disappear
which makes drawing envelopes a bit harder, I understand that unlinking the envelope from the clip duration would have some consequences as to what note(s) would appear when unlinked, but it would be super handy to have the notes shown somehow, perhaps similar to how you display multiple notes when several tracks are selected. Hope that makes sense.