I am not sure what "extra steps" you are talking about here.
Damage dealt.
Check Threshold.
Use Armor.
Mark HP.
Compared to a system with Soak (say, SWADE of Shadowrun) how is this extra steps?
First of all: stop saying "solo play." This is Duet Play.
Second, lots of extra (temporary) hit points is great but your action economy is still that of one PC. You're toast.
Ravenloft -- meaning the domains of dread -- are a giant pile of potential frames, given how frames are focused.
This brings up an interesting question: how would one do a traditional campaign world for DH? Would you have a gazetteer of all the lands (etc) and then a section on Campaign Frames...
That's one interpretation, but I don't think it is explicit in the DH rules or the only way to implement Aspects into.DH. DH is already a frankensystem, so bolting on mechanics is full with just changes to match the math should work.
DH isn't what I'd called either an extremely light OR a narrative first game. It is medium crunch, narrative second. So that would ask different things of a Delve frame.