Ok, now I'm eating my words And VERY glad to be doing so!!!
The steak was absolutely glorious!!!
Cooked on the electric grill - precisely 1 minute per side, alternating each side and angle (so 4 minutes total on the grill).
And one pic showing how the sear didn't impact the doneness of the steak:
Now, to be fair...I DID take those two halves and put them back on the grill and used my Searzall to crisp up that fat on the edge (another one minute per side, careful to not use the torch on my ceramic grill).
Now I'm disappointed it wasn't a rib steak....it was over far too quickly!!!
Reminder: Per my prior post, there's a 30 minute ice bath between the sous vide cook and the grilling - so you cool the steak sufficiently, so there isn't considerable cooking, only searing, in a short duration of grilling on a lower-temp BBQ.
P.S. (8 days later) - finally picked up an oven thermometer to test - the Weber Q2400 (at least mine, being a year old) only gets to 240C / 464F at peak temperature, so you have an idea of what alternatives you could try for an even better sear.
P.P.S. (a few days after that) - Weber support tells me that the max temp for the Q2400 should be as much as 550F. Working with them towards a resolution.