I've been running moonshine brew for the last 6 years now (no broken conrods but two broken cranks (awfull STS and a nice Nosram)... and shortened lifespan on bearings when I ran pure synth oil). I found (thanks Monty and Novarossi) that you need approx. 3% castor in the fuel to get a good lifespan and no premature wear on engines.
I'll start running Byron again. For me, the Race 25/11 is great for practise, for drivers that whats a really long lifespan on their engines or for drivers that runs their engines too lean = too much oil. The Pro 25/9 is great for racing but your engine doesn't last as long as with 25/11. As Neal told me, you don't need to lean your engine as much to get it run clean with low oil percent as you do with higher oil percent fuel.
I'll mix Pro and Race 50/50 to get the best of both fuels