UPDATE - No clue how, but somehow, over the weekend, this resolved itself.
Thanks @MustangSally - yes, I had tweaked those settings endlessly back and forth. Didn't notice any improvement, but who knows?
HOWEVER.. I did notice after the WW HOTAS installation/ setup, in DCS controls there were 4 instances of the Joystick device (yes 4! ) each with different device IDs (serial numbers/ device codes, whatever...) which being new to WW, led me to believe this was normal (?). Maybe one was the Base, another was the EX Viper 2 button strap-on, and the third.. well, maybe that was the shaker/ force feedback unit..??
BOLLOX. Clearly something went sideways with the install.
Then, In a Galaxy Very, Very Near... MFG Crosswinds to the RESCUE!
Miraculously, after connecting my new MFG Pedals everything resolved itself? (WTF?!) The 3 Ghost F-16 Hotas devices disappeared, and DCS welcomed my HOTAS buttons/hats/boats/sliders/coolies/flippies/slippies and whatsits with open wings. AWESOME! Ok, cool, I'll take it! Shout out to Milan, and his epic JEDI pedals. God help me if I ever have to go through that again.
Aaaaand now to spend the rest of eternity setting up the Orion 2, F-16 stick and F-15 EX throttle's 2 x 2n x 3n HOTAS buttons/hats/boats/sliders/coolies/flippies/slippies and whatsits. Aaargh. At least they work in DCS now.
#LovingDCS2.9Graphics!