I mostly listen to death-doom rather than strict death metal, but there’s a fair bit of that out there. My two faves in the genre:
Draconian has clean female vocals alongside growled male.
Swallow the Sun has a wide range of vocal styles, but getting increasingly cleaner pretty much every album (along with clean female vocals on a lot of tracks).
Again, this is death-doom so a lot of the stuff will be a little slower-tempo than straight death.
I have a cool idea for a facility to capture carbon in a non-menacing way. What we do is get a big chunk of land and plant a bunch of trees on it, then - oh, shit, I just invented a forest.