DERG, Could you please elaborate on what you mean by "fuel freeze"?
My understanding is that with most aero diesel engines running on Jet A1, the fuel would have to get to -47°C to get fuel waxing, and this also seems to be a thing of the past with automotive diesel thanks to modern additives. The bulk of fuel in the tank and the temperature generated by the work done in the injection pump would suggest these stay warm too?
I have heard of intercoolers overcooling under some conditions, but that isn't a fuel issue.
As for fuel cleanliness, why would this be any worse than for any other fuel or engine type? Aircraft, in most cases, operate in a much cleaner environment than earthmoving equipment, off road vehicles, etc. and effective filtration works for them.