>>88365393I think the subclass itself would have to have a more general focus on boosting summons, or otherwise handing out temp HP to allies. Hexblade doesn't have anything that specifically requires Blade Pact after all, so it'd be awkward to include anything that cared about Fine Familiar too specifically. Unless you gave it Find Familiar by default, that is, but then there's less reason to pick Chain.
The only real things you're missing after Investment of the Chain Master is a boost to the familiar's accuracy/damage (although damage is more secondary there), and health, obviously.
