What's different about front and rear of the master? Are the ports similarly sized? Or was the issue with the prop valve/ratios?

Yep Mike, I see some BBKs that never get near a track and when I ask a couple of very basic questions the answers tell me quite a lot. I have never understood how tandem duel master cylinders work. I've asked a few different "sperts" an the smart ones say good question. The dumb b#^&##s very quickly demonstrate they don't know either by their answers. One mob when asked what sort of psi might be generated in a cars hydraulic brake system suggested possibly around 100 psi. I didn't bother with any other questions.
kojab. Be mindful that I haven't yet taken it to the track with proper rubber on the ground. The front to rear bias may very well need more thought. It is certainly very nice as is just on road tyres. Pedal feel, feed back, initial bite etc. is excellent and very close to my 1998 Bathurst brake performance. Happy to have a yarn by phone. So far I've resisted pulling the hydraulics from the Bathurst and have given a lot of thought to that fluid level fluctuation that Paddy produced at the track. Does your car have the little baby brakes? ABS? What size master?
 Kris. Have a bit of a think about what happens with incipient pedal movement. Remember I don't have the faintest bloody idea what happens inside a tandem system. It's taken nearly 2 years of farting about testing and I've only a few days ago achieved a positive result.
The bright blokes "in the know" on track will never let me follow them. They wave me past, they pull off the track or dive into the pits. Tells yer sompin bout me brakes abilities up ter now.

Glad to hear that you are making progress with the brakes. Will you be heading out to Morgan Park any time soon?

Just driving it on the road and very much enjoying it at the moment.
But yes, Morgan Park Raceway probably in about a months time.
Do you have an approximate date in mind?

I have now spent two consecutive days at Wakefield Park clocking up about 300km on track.
Pushing harder than I have ever done before. And with some pretty good rubber on all four.
New bedded in Forza FP3 pads on my near new RDA discs.
Excellent brake performance. Slight chirps from tyres under really heavy braking. I think from fronts ? Hard to tell but it had no tendency to spin so I don't think it was from the rears. (Any time I've ever locked a rear the result has been a spin and OVER the BANK BACKWARDS )!!
Nice pedal feel and easy to ease into it etc. No fade even after getting stuck right up it for lap after lap.
There is some slight instability when under brakes but perfectly controllable. Probably being caused by the toe out I had been running in the front for the track days.
So at last I have achieved the beautiful brake performance that these little cars are capable of producing.
Certainly an adventure but that's what it's all about. I've learnt a lot.
Hope that giving these final results may clarify some of the points raised in this discussion.