Measure what? Are you mil’ing a target in moa? Where in your long range shooting is does inches it linear measurements come into play AT DISTANCE?
Rack width is a determination if a bull is legal in places up here. It's nice being able to range it and tell if it's legal or not with simple math.
Say a rack needs to be 40" minimum. You're looking at rack that measures ~10moa @ 405yds. Easy math says it's legal, or at least close enough to legal to be worth investigating further