Yes, it's true that glue can't absorb into the poly layer on the bottom of a Kamui Clear, but how is the poly layer adhered to the bottom of the leather tip? With magic unicorn dreams? No. The poly layer is glued onto the bottom of the leather tip. Isn't there some glue absorption in that process?
Yes, in order for a leather cue tip to stay on really well, the back of the tip has to be "primed" with thin CA. However, if your cue repair guy is soaking it with half a bottle of thin CA and turning the tip into a rock, he obviously doesn't know what he's doing. You only need to use a drop or two of thin CA to prime the tip properly.
I'm not ripping on Kamui. I like their tips just fine, and yes, the poly layer was a good idea, but the choice to use clear poly in order to make it look "cool" was intentional to create buzz about their product. Kudos for them, they are marketing geniuses.