Lee lived above Millaa Millaa lookout for a few decades so knows the Tablelands intimately. Lost count of the number of times you've ridden the Gillies, n'est ce pas, bruder?!
I agree about the non-need for off-road tyres. I rode the SF1 on road tyres from Darwin to Perth in 1975, but was offered a lift on that stretch from Broome to Port Hedland by a bunch of geologists heading south before the wet.
I rode the Halls Creek to Fitzroy Crossing dirt (290km) - it was bone dry and I loved it, fanging along at a nice clip but having to flatten it in some of the bulldust sections when I'd feel a potentially nasty weave setting in ... probably coming out the other side at 140+! Only way to handle it though. The guys in the trucks drove it pretty hard and to me the dirt looked similar to what I'd already ridden.
I've heard it's a nightmare once wet (as you discovered Cam). Also being on the brilliant dirt-handling SF

helped c/w battling with a pillion and a fully laden Z1!! I can still feel your pain, Cam - some residual damage there!!

. It's all sealed now, so it's all just history.
Bear in mind that an SF should give a much better range on a tank than a triple. I never carried extra fuel anywhere from Melbourne to Cairns, Darwin, Broome and south then over the Nullarbor.
Trip sounds awesome, Marty - wish I could join you!! Why is your cuz chickening out??!!!