We need a Keystone mastery for Squishy CC/utility supports

There just aren't any ideal options for them.

You don't take Bond of stone because you're squishy, and you don't want to invest in that tree, and even then, taking that damage for the ADC isn't ideal because you die so quickly.

You don't take Strength of Ages because you're not going to be killing siege minions

You don't take grasp of the undying because you're ranged and don't have a lot of HP

You don't take Thunderlord's because you're not focused on damage (so you don't have APen or AP), and chances are good you'll have a hard time chaining 3 spells together

You don't take Stormraiders because you're not going to be chunking 30% of targets hp

You don't take Deathfire because you're not going to have enough AP to take advantage of it

You don't take fervor of battle because you're not going to be consistently auto attacking

And you don't take Bloodlust because you're not going to be building Crit.

That leaves windcaller's blessing, which is 9/10 only going to impact 1 of your skills and fall off hardcore end game. CHampions like Janna who really emphasize their shield do okay, but on champions like Bard, Morgana, and above all else, Zilean (No actual shield, and Bond of Stone puts his passive on a 10 second cd every time the adc gets hurt) it really feels like there just aren't any good options. There needs to be something that supports a playstyle of utility. Something that helps supports who focus on CC and utility that isn't just shields/heals. And at the very least, let windcaller's include speed boosts.

TL;DR: None of the keystone masteries feel like they support a utility playstyle that certain supports maintain.