I apparently missed this post last year. Caught it when Dan replied. I think we talked about this on the phone. But for the benefit of others, I'll do an actual reply.
As a disclaimer, I've seen both boats here, but never at the same time.
The SE runs the halyard back down the inside of the luff track, instead of down the front of the mast like the SC. That's why the SE has a hook at the top. If you put as much tension on the SE masthead as is on the SC masthead, you'd torque the masthead right out of the Comptip.
It's not a matter of the block strength. It's the leverage exerted on a pulley system offset from the vertical axis of the mast. You'll pop the rivets at the front of the mast cap... Or worse, rip out the glass in the Comptip.
And I don't think the SC masthead will fit the SE Comptip (Matt?). Yes, the two heads are different. For others trying to keep up - the SC head looks like an H-16 head (dual sheaves). The SE head looks like the 17 and 18 heads (single sheave).
And... I'm willing to bet that even if the SE and SC use the same extrusion that the SE Comptip is significantly longer than the SC. So no, Dorothy, you can't use an SC comptip on the SE.
I do understand the reefing issues. I just don't see a good solution.
There's nothing wrong with climbing the mast. Just ask Aris...