Chris,
I am currently doing the in shop TPI on a Sideplate job going to CA. The company I am working with is starting a second one in this Fabricator's shops here in AZ this week.
If you have a chance to go through ALL the engineer's structurals and not just the shop/erection drawings you really need to do so. A lot of questions will be answered. You also need to go to a meeting they are supposed to have before beginning that covers all the aspects of their holdbacks, one hole dimension, Z dimension (not related to Z-loss), pre-heat requirements, and other specifics. They usually do this with a powerpoint.
Their system takes D1.1 & 1.8 to new heights. Watch your undercuts, arc strikes, and other criteria very closely. The CA inspectors (OSPHD) are terribly critical, beyond the scope of the codes. And yes, they will try to get you to reject things that are not beyond any of the inspection perameters. We have fought back on several items, but they can make it hard on you if you don't just comply with their demands.
The mock ups and seeing them after testing were awesome. The stress that this system will take compared to standard moment connections is far and away superior.
I hope you are working with a real good and serious fabricator who has a good detailer and is interested in quality. There are many aspects of this system that won't work if someone messes up.
Have a Great Day, Brent