the undersized steel.plate was in there to make the stack height correct, there are multiple thickness to insure this, so I don't think that was an issue.
Kaw oem frictions are very consistant, I have done many stacks simply using new frictions, presoaked.
when you did your swap, did you follow the manual, specifically on locating the outermost friction in the next groove of the basket, so it is trapped, per the correct sequence, or did you just stack them all in the same slot?
just asking, have to, because 8 out of 10 people doing a replacement don't have a book, nor realized the outer plate sits in a different groove, to allow correct function.