When I was doing tract houses we had about 6-8 floorplans depending on the development. After about the first 25 or so houses you started memorizing all your measurements because they would of course be the same for each floorplan of a particular type. In high rise work is it similar in that respect? Are you able to set up any kind of production where an apprentice has a little room somewhere with a nice vice set up and a table and just cuts up pipe to the specs you need in every unit. He could have a bunch of those plastic tubs set up with 30" x 2" copper risers in one and something else in each one or whatever.
While I was an apprentice or I may have been a journeyman at this point I can't remember, I spent one day a week at the shop for a little over a year just building Delta 1300/1400 tub and shower valves so that everyday the crews could take pre assemled rough in valves to their houses. I had to have built close to 1000 valves that year. It was a good idea for several reasons: 1. quality control - if their was ever a problem like a leak or burned up cartridge they knew who to see about it. BTW there was NEVER a problem with ANY valve I built

. 2. I got very good at it and very fast. Although this was factory work which I hate anything that resembles factory work there is an economy of motion when you don't have to set up every time you want to build a valve. 3. I developed a standardized version of the valve which helped the guys be faster because they got the same product every single time.
I know commercial work is much slower for a variety of reasons and maybe you are already maximizing the economy of your movement but I'm just wondering if some things might be able to be "mass produced" to some degree?