[Bugsinrugs]

I do flooring for a living. I determine the most exposed line of sight and make that straight. Always try to measure off an outside wall as these are usually straight. If there are any small or out of square cuts have them go where furniture will hide them.
In your case I would take lots of measurements and get that stair nosing piece as square as possible. It will always be exposed. One can put in a click floor in reverse but it takes more time. If it makes the job come out better I do it.