Your comment about afr going rich smooths it out. Do all the plugs look the same when removed? Have you thought about doing a compression and leak down test?

 

Last time I looked the plugs looked the same, but I think I'm gonna throw another set in there just to be sure they're not causing this, Leak down test showed less than 6% and compression was around 150 for all

 

Sorry, forget you said all that.

 

Its because your ISCV trim is is way positive.

If you do the process in smaller step and wait each time for the trim to come down, you'll get it set.

its seems that when the trim is very positive and you adjust the BISS, the RPM goes up too high and the ISCV wont compensate. Least that's what Ive seen on two cars recently. Making the adjustments in smaller step and waiting for the trims to adjust it, worked in both cases.