and so are most of the new FADEC controlled engines on all model types.
It's the fuel metering concept that requires close clearances, not-too-tight and not-too-loose, just like a musical valve instrument.
ALL fuel controls - FADEC and pure Hydromechanical - are sensitive to contamination - lots of moving parts with tight clearances. The RB211-524G/H was much worse due to even tighter clearances than is typical for most controls. Lucas (now part of Goodrich) liked to use much tighter clearances for their valves than the other guys, and it caused problems the others didn't see.
OTOH I know very little about the Trent 700 - I don't even know who supplies their Fuel Metering Unit (i.e. is it the company formerly known as Lucas, or is it someone else).