> You are inventing problems

Sometimes that is how useful jumps are made. Maybe someone will come along with a problem and the data they have just happens to have similar properties.

Rather than premature optimisation this sort of thing is pre-emptive research - better to do it now than when you hit a performance problem and need the solution PDQ. Many useful things have come out of what started as “I wonder what if …?” playing.

This is research, not production code. Premature optimization is irrelevant.