2010-2012/13 1->2 shift shudder ATX?

Title says it all. Once warmed up, my '12 DCSB V6 with the A750 has a nasty shudder during a partial-throttle 1->2 upshift (i.e. in stop-n-go traffic). Another user here posted something similar about a month and a half ago about his '13 DCSB and got no joy from his dealer. Neither did I (though I did get the driveshaft TSB done for the clunk-on-stop condition).

Well, I guess 4Runners from MY2010-2012 have this exact same problem. I took a used 2011 4Runner for a spin from a local used car lot, just to see. Sure enough, the problem is the same, happens at the same speed, same conditions, etc.

The 4Runner TSB is TSB-0089-12, but it does not apply to Tacomas. I searched TIS this morning and there is no analogous Tacoma TSB, either. So, if you have this issue, gripe at Toyota Corporate, your dealer, or both.

BTW the fix is a complete R&R of the A750 and an ECU flash.