OK so I found out Bilstein now doesn't even rebuild their own shocks anymore.
And Glenn Yee contacted me back. WOW. It's a no-brainer. Glenn (not an employee or secretary - Glenn himself) called me (not emailed back - called) from his cell in his car. Talked for 45 minutes about tech stuff, performance options, possible causes of my different symptoms, life in California and Tennessee, etc. That's a lot of time for a guy he's never done business with and for such a small job. What a great guy, full of knowledge (50+ years experience racing and building Porsches) and genuinely interested in fixing my issues without overselling me anything.
He quoted me $600 for the rebuild labor plus $100 for the basic parts. No extra charge for cleaning the struts or removing/reinstalling the springs like other places (he encouraged not to do any of those things), AND springs and struts will both be tested, strut dyno chart printout included
Sending the coilovers to him in a week or two, then replacing the parts he recommended while I wait. I'll report back when everything is done.