Okay, now that I've studied the car's behavior and came off of my panic, I have a better grasp on what's going on.
Since the rear tires are smaller in circumference, the speedometer reading is now 5 mph faster than before (used to be 1-2 slow, now it's 2-3 fast). The front tires are the same size, so the car is suddenly seeing the rear tires going faster all the time, which I believe is disabling regen. That doesn't make much sense to me unless I can see how the car's coded, but if the rear tires go slower than the front (hittting bumps, slick roads), regen will get cut back then brought back up. Maybe the car is programmed to cut back regen if speed difference front to back is 2 mph or more, but not set to disable regen only if the rear tires are going slower, just a general 2 mph difference. Funny thing is, if I go around a turn for about 3 seconds with the wheel past the 10 or 2 o'clock position, regen would come back.
I've adjusted my tire pressure to help make the situation better (44 on the back, 36 on the front), but it's still not right. I'll call the local dealer (not the one I bought from) tomorrow morning to see if I can get an alignment and the speedometer calibrated. I'm not sure if the car will make it to the other dealer the way it is right now.
One interesting note, if I coast down to 25 mph or less and tap the throttle, regen comes back, even on straight stretches.
"Bear" - 2012 Diamond White Pearl ES with QC - 2/21/2013
Solar-powered since 10/10/2013
"Koorz" - 2012 Cool Silver Metallic ES with QC - 1/5/2015
2017 Bolt EV LT in Orange with QC - 7/31/2017
Driving electric since 2-21-2013.