If you play with them, you won't void your warranty.

Instead of lowering the left side, just reindex the right side to go higher. Dealer should have done that instead. Now it will be harder to align, not easier.

Different spring rates for the left and right side? I'm not aware of such a claim, but I'm not an expert in the production spring rates of these t-bars. But I'd have to call 'Bullshit' on that one, personally.

I do know that most t-bars will sag. Sooner or later, that's the only difference. One way I can tell an older D21 or WD21 needs an alignment, look at the gap between the fender and tires, and compare them front to rear. If the front is lower, needs a proper alignment, or the current alignment is a hack job!

Anyway, Calmini or Nismo, either way, you're a winner.