"Open Class" could mean open. High mag scopes, clicking, hold over,bum bag, shooting jacket, harness, bucket & sticks. This would allow shooters who have been in open , but whom for what ever reason( medical,age) can't get on a bum bag,continue to shoot, with out having to learn how to re-range with 12 power scope.Some shooters find the 12X scope and using hold over frustrating(which is why they started freestyle)
I shoot "hunter", I like hunter! Not sure how many hunters would jump to open class, but I would not. Started field target in hunter, so never had the pleasure ranging at 50 power & clicking. I don't care what the shooters score is in open or WFTF. Different disciplines, so not a issue.