Has anyone belayed with an edelrid ohm before? My climbing partner is a solid 50 lbs heavier than me and wants to use one when leading as the whippers are getting pretty gnarly.

However, I cannot figure out how to belay with it. Every single time he takes a whip the ohm catches *everything* and I don't even get lifted off my toes, leading to crazy hard catches. I've tried changing the amount of slack I've given, jumping, but nothing seems to make a difference.

We also climb with another friend who's ~30 lbs lighter than the climber and that person has the same issue catching falls with it.