< Artefact
I had a premonition about that :)

< does that solve the problem for you? "Add detail to inflections"...
Surely but as I am always at same default regulate, "add details" disable, it's the same for your model so pertubating :)
Because mine has not!

< Probably you've got some duplicated
He he
It was just the start generator curve of the original of Kevin's model so resolved :)

And yes with the fillet Shell is some better!