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certain lengths and cadences will just feel better for some people
Yes, since there's nothing to be gained by changing within the normal range, there's no harm in going with your personal preference.
All of the above assumes you're only interested in making power in comfort. At some point, we have to consider that it's not a "physics problem" and look at how crank length limits positional options which might be aerodynamically advantageous. Outside the dyno cell, the actual task is to go as fast as possible, not just to generate power.
But while the numbers might be constant, there’s no arguing that certain lengths and cadences will just feel better for some people and others for others right?