My home airfield (where I think you did your QXC) has a 1000' circuit but I honestly don't think I've ever looked at altimeter after the end of the downwind leg. I've flown short and long approaches, to fit in with other traffic and never really thought about my height at a particular point of the approach, unless it all starts looking wrong.
I think there are too many variables, e.g aircraft performance, configuration, surface wind etc. to plan the circuit 'by numbers'. As long as you fly the right approach speed, you'll always be able to get the height off by S turns or sideslipping. There are plenty of visual cues to tell you if things are working out or not and never be afraid to go-around...it doesn't mean you've cocked it up, it's a good decision!
Have a good weekend...hopefully you're coming back to one of your QXC haunts!!...Buy some fuel & you'll get a cheap landing fee!
BTW, I'm not an instructor, and with 170 or so hours, by no means an expert!...in fact, maybe I'm just gash!!