This shudder issue is largely dependent on the friction level at the flex-lock clutch, which is mediated by the transmission fluid.
In cases like yours, out of warranty, I would firstly have a thorough fluid replacement done, preferably a full drain-out and refill then with the cooler hose allowed to drain the torque converter a couple of times with the engine running.
Note that the popular synthetic fluids that meet WS specifications have a higher viscosity under standard conditions (however still meeting the specifications over the entire temperature range). So these up-rated fluids from Amsoil and Redline (or even the inexpensive MaxLife) would seem to offer the chance to soften the torque pulses from the dwell-modulated, cyclic applications of the flex-lock clutch, which is the source of the shudder.
If the fluid change does improve your transmission's shudder, then I would follow up with a pan-drop fluid and filter change. There is rather little to lose here, yet the payback is enormous.
You could even take one more step and add a friction modifier, but don't take the cheap/lazy route and use such a product first! Definitely a last-try sort of thing after a very thorough fluid replacement has been tested.
You didn't mention how many miles are on your car's trans fluid, but it's not a lifetime fluid in the real world, especially for these pre-2015 cars.
Lastly, don't wait and keep driving a car with shudder. The shudder likely develops a wear pattern on the clutch surfaces which might be harder to correct with fluid replacement after it's been going on for a long time.