It must also be understood that overdriving the front is only of benefit if you start with the fronts smaller than the rears. It changes the front geometry slightly and also the smaller tyre will act harder.
Well that's a given. If you don't true the fronts you get like a 1.07 OD ratio which will cause great stress on the front belts. I've been running with the 16/19 setup with the split for about 5 months and haven't snapped a belt, not even close to it. The ultimate proof for me was when I saw how consistant my lap times were in a main from beginning to end compared to the stock setup. 3.5 to 4mm split is the magic # for me.
Is that 16 front 19 rear?
No, it's 19 front, 16 rear and again, the only way you get the benefit is by truing the fronts(3.5-4mm). If not, it's just as good as driving with the stock setup and the rears worn down.