I’m assuming it cycles better the the BR
To be honest, I don't think so - the round length and the feed lip support in final feeding are exactly the same for BR and Dasher. Personally, I think a lot of guys short stroke their bolt too often and like blaming their rounds or their mags - George Gardner and Tom Jacobs invented the 6mm GT to "solve the feeding problem with Dashers," and a lot of us were scratching our heads as to why - I can run my Dashers in mags without blocks and feed just fine. But then a couple of years later, George worked with MDT to revamp their magazines because GT's weren't feeding... And again, a lot of my folks are scratching their heads as to what was going wrong that folks thought GT's weren't feeding... I have a bunch of 6BR cases from one of my old barrels that I've ran as dummies in my match rifles - I just can't get them to choke. Hell, even feeding into my 6 Creed barrel in my Seekins action, I can't get them to choke... But apparently a lot of folks have issues, so we made new cartridges, new followers, mag blocks, and new mags to solve a problem that I'm not sure ever really existed...
I'm more prone to think that more rifles are getting slapped together by folks who don't know what they're doing, because drop in stocks/chassis' and headspaced drop-in barrels are more prevalent, but nobody is actually checking to determine if these rifles will actually feed worth a piss once they're assembled. But it's an unpopular opinion...
I'm not sure the point in talking about anyone "stealing" anything - and I might point out, for all it did for the Dasher, BR never had the momentum to promote factory brass be made. I started shooting Dasher over 20yrs ago, before the PRS came around and LONG before it was even adopted for "Police/Tactical matches," because it was a great specialty pistol cartridge, and it wasn't until a few years ago that I could buy factory brass with a Dasher headstamp and shoulder ready to fire. It's hard for me to justify a full swap from Lapua BR brass, but options exist today, and it wasn't because of Benchrest shooters... Were it not for Magnetospeed and the T1000, PRS shooters never would have adopted the 6 Dashers/BRA's anyway.
PRS just isn't a pressure game, and we don't benefit as much from velocity as do the group shooters - our targets are pass fail. Yes, my 6 creed can make my targets 0.2 mils wider than my Dasher, but it also pushes me off of target a lot more. PRS a high volume reliability game where recoil is a significant penalty. When I started 8 seasons ago, some folks WERE still pushing pressure, and I carried a solid steel cleaning rod with a blunt jag on the leg of my tripod because at EVERY match, someone on squad around me would need to knock out a stuck case that failed to extract, either because it was raining or it was hotter than when they did their load dev, or they'd never shot the rifle through 250 rounds of a 2 day and their fouling condition was causing increased pressure... or we'd all be cringing in the latter half of a match day while we watch a shooter bruising their hand because they had to slap their sticky bolt open on every stage... I never needed the rod myself, because I was pushing a 6 Creed at Dasher speeds. Now, I push a Dasher at BR speeds. Cases last FOREVER and I never get extraction issues or sticky bolt.