Whimsicott and Toxicroak are examples that wouldn't necessarily mind less defenses for greater healing to mitigate Substitute dmg.That'd be crappy it'd pretty much negate up it's usefulness with the defense reduction
But that choice buckler idea Is interesting... I don't know if offensive natured pokemon would appreciate it though and I don't know any defensive mons that want to be locking into a single move.lol
Also, he said Choice Buckler would disallow attacking moves. Basically, a reverse taunt that makes you total taunt bait, but with boosted defenses.
I think both items would be niche, but cool additions. GF needs to step it up bc most of their "niche" item introductions are simply "outclassed" rather than niche alternatives.