I have 2 Atlas bipods, both the previous gen and the newest. When I back the tightening knob off my cant is quite loose.
I prefer my cant to be very tight anyway but you should be able to loosen it up. Your opinion of stiff may be different than mine though.
BT Industries has amazing customer service and if you give them a call directly they should be able to help you out. If Kasey picks up the phone, he is the owner and is a great guy. I have talked with him on the phone for hours chatting, and met him in person at SHOT this year.