I was thinking that if the guide step was machined away to accommodate dual springs, you would have enough seat room for the beehives. If there were any "centering" concerns, a spring cup would help.
Although I've had good luck with their beehives, I have to admit that I haven't had the luxury of individual spring testing, just going by their charts. The only problem I've had in my race application was several years ago. I found a partially broken retainer and others kind of beat up after a few seasons. I shimmed them for 20+ more lbs of open pressure and everything seemed better, including maintaining valve adjustments.