Allow me to.introduce myself. Built my first wheel in 1966. Built countless wheels since, mainly for racers and tourists. Before THE BOOK nobody had tensiometers. The only one around was the Hozan, which was only used as a QC tool in factories.

Even tension wasn't an issue, because rims were much lighter, and it was difficult to build an aligned wheel with uneven tension. Some rims, including Fiamme Yellow Label, and Araya track rims were so aquirrely that the least error would show. Even with no conscious effort any decent builder was consistently producing tensions within 10% purely through good technique, and calibrated fingers.

When I started distributing Wheelsmith spokes sometime in the 80's I swiped a tensiomerer from stock, and still use it to check my "calibration" taking 3 readings off finished wheels.

Like other old tech builders, I still use my thumbnail and ears to confirm that tension is uniform.