Mark, looks great!
As I understand it you used regular store bought past & homogenized milk, not UP milk, it was just the cream that was UP. Store bought cream and Half & Half in USA is normally UP milk is just normally pasteurized.
I've used only UP Half & Half
in my Cream Cheeses
and they came out OK, but when I used only UP Goat's Milk in a Chevre
I couldn't get a good curd set, at least with the amount of rennet I used.
I don't think the limited amount of UP cream you used (1 cup in 2 US gallons, ie 3%) was the cause of your long curd set time, may have contributed but not cause.
Bit late now bit if you give details of your ripening & rennet stages I'm sure some of members can help find reason for long curd setting time. Would help you on your next batch.