" I imagine the vinegar will dull the finish over time"

Why?

What finish?

I suppose if you use too much vinegar you could begin to have a reaction with the floor. BUT you dont need vinegar everytime you clean the floor. And when you do use it it should be diluted so much that you can barely smell it. I usually recommend a cap full or two per gallon of warm water. But you have high gloss finish and want to keep it spotless? Good luck.

Once you clean it and then never walk on it again is the only way.
You are going to have to live with minor footprints and smudges until you decide that a gloss finish isnt worth the upkeep.

Changing the sheen on your floor isnt a big task as long as it meets some criteria. A simple buff and coat can change the sheen b