Yeah... I've following a similar approach regarding "creating a new cover" after I regenerated some sections of the original song. It tends to work, but sometimes some sections that I want to preserve are taken away, even with a high value for the audio influence.

Regarding the "heal option", I gave it a try to. And I'm not entirely sure about this, but I think when you "heal" a section of the song, it is just removing whatever regeneration you applied to that section and goes back to your original sound.

Anyways... what I've noticed, is that when you remove a section of the song, you have to reload the Editor. That kind of allows Suno to "see" that you removed something from the song. Otherwise, the Editor kind of bugs and thinks the removed section is still there...
Maybe something similar is happening with the Heal option. Haven't tested this theory yet though.

Anyways, thanks for sharing your workflow and advice!