You'd have to go back to a build that doesn't have the problem (I don't know what that'd be as fixing the issue instead of trawling back through old code commits was a better use of my limited time at the weekend). The spawning a new process shortcut from the current instance or using the /new command-line action when also relying on the use of another provided settings folder copy for it to use is what's triggering the problem to occur so for that I don't have any nice workaround unless you make another unrelated install & then mess around with trying to copy the existing second instance's settings folder into that or just doing it all from scratch with 2 different installs.
