I'd agree... I don't know for sure, but I've wondered if this isn't a downside of the boxer design... with the heads on their sides and a literal direct path from the topside of the oil pan straight into the PCV circuit, I wonder if it's related to windage/vapors. In city driving and even rural 2-lane driving, I never really saw oil consumption on any of my Subies. However, toss in hours of Interstate speeds (3k+ rpm) and magically some consumption appears, only to disappear on the next OCI where you didn't take that road trip...
However, the FB25 in my fleet doesn't use any oil regardless of usage modes.