Good onya jet. Glad jab have treated you well, but like you said, you havnt had any issues with your engine yet ay? So applaes for apples..your selling oranges.
When did DS say he ran a mixture of fuels? He ran 98 octane. Very rarely the tanks got topped up with AVGAS. in the 300 hours in question, probably 30 or 40 litres TOTAL avgas.
What SB was not carried out on these two engines?
As far as im aware jabiru haven't recommended W100 oil for some time. I could be wrong but i recall them insisting we change to 15/50 some years ago.