I have something to add. I replaced my injector seals last October with Alliant AP0002. This kit included the top ol seal. Recently I experienced a hard hot start which can be read about here. https://www.ford-trucks.com/forums/1...ues-again.html Last night I pulled all the seals from the opposite side and discovered more of the same type of damage except for one seal was perfect.
I called the retailer and described my findings, who in turn called Alliant. The story I got was that Alliant had a bad batch (too soft a compound) of upper oil seals which explains why some of the rings were good and some were not. Apparently some of the rings I got were old stock defective and the good ones were new stock updated material. From what I understand Alliant will warrantee them if they are found to be defective. I'm not sure if all the issues creator experienced were the result of nipple seal failure or if crappy oil seals were partially to blame.