My concern with curvature in the XF12 stems from this review
http://www.cloudynights.com/item.php?item_id=1438 - see field curvature graph towards the bottom of the page. I have the XW14 which shows significant field curvature in my dob; the XW14 would perform at its best in a longer focal length Newtonian or other scope that produces a relatively flat field.
I imagine the Hyperion would perform poorly without the bottom lens group, but in any case I'm not a fan of taking eyepieces apart and risking getting crud inside them (such as dust or blackening off the threads).
I'd still urge DJVege to go slow and explore your observing habits with the eyepieces you already have(assuming you have a few plossls).