I don't think this is a particularly great idea, but it's better than doing nothing. Those who want strict ranked can get it, whereas those who wish to be competitive but don't mind quite as much can go to special. I still think that the best solution is fixed CaS with forced random stages.
And when I say fixed CaS, I mean the following: when you make a character the recommended size, its hitboxes and general size match the original character identically. Going above or below would scale this up or down appropriately. Only recommended size characters would be permitted in ranked, and characters that have certain elements would be blacklisted (such as multiple thunder god drums, or any special accessories located near the front of the crotch). CaSes that check out for competitive fairness could possibly be specially marked, such as with the recommended height star in the corner of the character's picture. Or maybe CaSes that don't check out could be marked instead.
Namco puts a lot of work into this feature. It'd be a shame to see it fall to the wayside for an entire section of the playerbase.