Thank you! Well found, subdetective selenak. (As you can see, I got distracted by other FW shenanigans.) So FW does *not* always obey the Reichshofrat. I can see why he thought this one was well within his rights, and why the Emperor decided not to push it.

I have a related article, on Austria and Prussia in the Imperial Diet 1745-1763, that looks interesting, but I'm waiting on Royal Patron for the download.