A good start would be to -reduce- the presence of additives in jet fuel, some of which are designed to absorb water (dessicant). What was once a smattering of tiny manageable crystals of ice is quick becoming larger chunks that cannot always pass cleanly through the system.
I haven't seen this mentioned before, and didn't know that additives are water absorbers.
Having once overdosed a garden pot with water-retaining gel granules, I'm aware of how dramatically such materials can expand. (Looked like the patio had been attacked by flying jellyfish.) If the additives in fuel are in any way similar, is it plausible that they could form lumps large enough to cause problems?
If the fuel contained very little water, might this be a reason why?
Not a pro, ready to be put right...