I'm kinda with BrewerGeorge here...it does encourage DOS (at least most people say so), so there would be no reason to use it as a super fat, even though it won't stay that way.
All the salts will metathesize (called, unsurprisingly, salt metathesis), even after cooking and you'll end up with a proportion of your fats as super fat roughly equivalent to the percentage of fats in the total makeup of the recipe after a while.
That having been said, if you stringently avoid the use of linolenic (and linoleic just for good measure) acids in the rest of the oils, you could certainly use oils that contain a high percentage as long as they're used at low proportions in your mix. 2 to 3 percent of even 100% linolenic acid probably wouldn't cause a problem; I never ever go over 15% total linolenic, and I try to keep it well under 10.
If yours ends up at 5-6 between the added oils and the base oils used in the HP cook, that's highly unlikely to be an issue.
But again, don't expect your soap to act, over the long-term, as though your super fat were pure linseed or pomegranate. It won't and the fats are going to slowly react while other soap salts react out to fats.