It's a fair point; I'm not sure where you'd draw the line between physiological effects and skill effects and equipment; things like ligament spring-loading sound like they would be subconscious techniques that are also accompanied by physiological adjustments.

And I am sure that you would make a physical adaptation to a sufficiently different frame/fit geometry, though if your fit was "good enough" then upgrading might not incur much change on the physiological level.