While it surely must factor in for some folks, and be a spicy ingredient in a given dynamic or arrangement, I really don't think that size in and of itself necessarily drives the impulse. Nor does smaller size confer some requirement or necessity for caging. It's up to the couple! But there is something about a small cage, for sure, and lesser-endowed guys can definitely fit into some really tiny ones...I can attest to that. I also think it’s a thing worth trying, at least if you've thought it might be for you.