Well to answer my own question, yes it's recommended to cut the studs. I called Daystar Cust Service and they told me the stud extenders should be flush with the strut top plate. So I cut the studs. Honestly, it made about 1/64 of an inch difference and still wasn't all the way flush, because the stock studs aren't threaded all the way down.
XREAS took all the fun out of the job, probably 6-7 hours working solo. Urging the back stud with a hand held back saw blade is not fun, especially with the XREAS hydraulic line at full extension. Got everything back together and started testing, and my left CV is binding at full droop. It's a new NAPA, not reman. The stock CV that's leaking with 170k on it spins fine. I'm hoping when I reinstall the sway bar and get an alignment, and let the lift settle, the binding goes away. If I jack up the LCA even 1/8", no binding at any point turning the wheel. Drop the jack to full drop and it binds by hand. Bummer.