Hola Scott -
xxx
Yes, in the USA, many airlines do a "climb check" at 18,000 feet, like switching lights off, and twisting the altimeter to standard at that time, maybe even call the cabin staff for an "emergency" cup of tea. As 411A says, other airlines, other countries do all that "climb check" at 10,000 feet.
xxx
I see you are at Mt.SAC... Used to lecture occasionally there in the 1970s, they have among the best aviation curriculums. Lots of famous people were around there too, Ray Lahr (designer of the CR-3 whiz wheel), Clay Lacy (famous pilot now retired from UAL, Learjet/FBO operator, and speed records and his College in the Air flying a UA DC8 with Mt.SAC students over the N and S Poles). Is Bob Thomas still around...? (Captain and Training Mgr. with FedEx, ex Flying Tigers) - Well, you are in good hands. The who's who of Califonia aviation is there.
xxx
Unfortunately I am far (in the Deep South, Buenos Aires, ARG), I am an ex PanAm, still flying 747-200s and soon to retire on a Brazil beach as D.O.M. (dirty old man), but if my buddy 411A cannot suggest answers to your questions, you can always hit on me, I still remember FAA rules are. Where do you fly from...? Riverside, Chino...?
xxx
All the best to you -
Happy contrails