Enhance Item (Schema:
"When you create an item with this feat, adjust the DC for saving throws required by the magic item, if any, by your key ability modifier."
Dragon 317's Truename feat:
"A spell completion item functions as though the spell was cast by the truename-using spellcaster (at their current caster level, adding the user's appropriate ability modifier to the DC and other applicable bonuses, such as the bonus from the Spell Focus feat) without increasing the item's caster level for the purposes of creation or another's use."
So...who wants double their casting mod to spell DCs?
Argument for: Enhance modifies the crafting process, setting a new DC for anyone who uses it. Truename ADDS to it when YOU use the item.
Argument against: Truename treats you as the caster, possibly overriding anything the Enhanced item had going for it.