On a more serious note, what relevant utility did SCH bring to a Skip Soar Zurvan PF that WHM couldn't?

Shields? Didn't need them. DPS? You didn't even need DPS jobs to skip soar.. MP? Zurvan had long enough intermissions that it wasn't really a problematic fight for WHM back then.

No, the reason why some Zurvan PFs blocked WHM was because they saw the problems the job was specifically having with MP in A12S and how outspoken the raid community was about it and came to the conclusion that WHM must be DOA for Extremes as well.