Unfortunately because Special traits are infinitely open ended, I'd rather not do it for most because there's no way to "categorize" it I guess, like how the exchange of traits is for the lower tiers.

The only thing that would really be passable for example is changing a mismatched puff tail to a full giga puff or wing fings into feathered wings--stuff that works by relation. So it's case-by-case but you wouldn't be able to trade ears for tail.