I would still send the original request to the D.A. and copy the CHP. But that's just me...
If they fail to provide you with items in your request, you can make a motion to compel... If they provide the items past the 15 days but before trial, you already have the material so you have no reason to complain!
I'm not sure where people get the idea that the officer will change his testimony or the evidence he presents based on what "evidence" the defendant has... but, if you feel your case is different, and since you're requesting evidence from them, you can reciprocate and provide them with what you have. Though I doubt they'll complain if you don't!
Realistically, for a 22450 citation, what else besides the officer's notes are you requesting or what are you expecting?

