Chlamydia Resinae is one of the little bugs that like to live in hyrdocarbon fuels, I have occasionally heaved a plug of it outta the fuel-filter on my Diesel Toyota Troopy.
How about using centrifugal oil-purifiers like they use on ships to remove crud,
Chlamydia, water etc from fuel? As for the problem with freezing levels, why not either heat the tanks or use a lower-temp blend (e.g. Alpine-blend) which I understand is regularly used in the Snowy in winter.
Would love a little diesel for the microlight but the power-weight ratio of the Rotax 582 is very hard to argue with.