So I got a new nib and feed for an old Sonnet from Dutchpen, it wasn't exactly smooth and skipped, but I thought "hey it might be a used nib, can't expect much" but after writing more with it, it's become much smoother and has almost no skipping. Moral of the story: don't give up on a nib. The other nib I got from Forecast pens is the smoothest I've ever tried, apart from my Sailor Pro gear Standard with a 21k nib. These Sonnets can be very enjoyable!
The one on the right is using Yama Guri, which I think finally found a good home. That Fabriano Taccia paper is quite nice too.