I donno but it's just my personal expereince. I tried so many times with my PN1012 for texture string like Prince Topspin or softer string like natural gut. The clamp cannot possibly grip these type of strings tight without putting excessively pressure on the string. The only way I can use them is by inserting a business card in between. However the Gamma 5 tooth clamp just grip on the string no matter what. Don't get me wrong, I still use the PN1012 for normal synthetic gut or poly as it is easier to adjust and easier to string the cross. But I would prefer the Gamma 5 tooth clamp for any textured or soft strings.
Maybe we are using different machine but the PN1012 is actually too short for the Eagnas spring assist clamp base on my Combi710. I usually insert a binder clip to raise it closer to the string bed when I start the main and don't feel like using the starting clamp. IMHO, the taper on the bottom doesn't make any difference at all in terms of fitting. It simply allow you to insert the clamp into the base easier. The taper part won't even touch the base anyways while you're stringing.