To lean a mixture :
with Blue you have to MOD the AFM signal so timing going bad
with Ultimate you could MOD injection directly
overall you could use 540 on both but not with the same tuning method.
With a pressure sensor you could emulate the AFM signal on Ultimate, not sure you could on Blue.
You have to add a manifold temp sensor to make adjustment on inj and ign, could be done on Ultimate, not sure on Blue
I had an EMU, i am now on a standalone (easier for fine tune), EMU is a good piggy as the last MAPECU (they share the rpm vs boost vs AFM output signal to start with), i tried a Blue one on my 205 but i don't like the way you adjust AFR (affect timing) as a SAFC with bigger table so remove it and look after a 2nd EMU or perhaps a standalone (expensive for a DD)