I hopped into Saint Denis and walked around and within ten seconds my game had already started stuttering like mad. I quit out, changed that line in the xml file, loaded back into the same exact scene and my frame times were smooth!I maybe found something:
There is a <asyncComputeEnabled value="false" /> line in the settings.xml
I've changed the false into true and the Vulkan stuttering is gone. GPU utilization is down by ~4-5%. Performance is pretty similar though...
No idea what this setting really does, I thought async compute was always "on" in this game.
Maybe the stuttering is gone because of the lower GPU utilization? I don't know.
I haven't tried this for long, but maybe give it a try yourself.
Thanks so much for finding this! That stuttering was really getting on my nerves.