So the discussion recently with a few of my friends who are elite pro racers fall into my own school of thought, use every gear to the max, example rolling down a hill & starting up the other side banging every gear to the max to get the most speed out of your spin & gear, damn the chain line. I know there are certain riders that would never consider this, puss or not? What say you?
Go back to the 50's setups, with the final drive up front on the captain's crankset, and the chain will be long enough it wont matter at all .
That's how I set our bike up when it was used as a kid-back tandem - certainly no chain line issues. But even with a normal chain setup I don't worry too much about cross chaining. Depending on the details of stay length and BB length one of the extreme gear positions may feel rough and be noisy so I'll avoid it. But if it feels and sounds ok I don't worry about it.