The Max con check is usually completed post ECU change to ensure that the Ng governor is set correctly and the expected values of Ng/T6 can be reached without NR decay - ie that the engine is performing as advertised and therefore the performance figures from the ODM are reliable (predicted height loss/Min SELF).
If the Nr decays before the figures are reached, the Ng governor is set too low (had this on a couple of occasions).
If you get a sloppy cyclic in a Lynx, I refer you to Shy Torque's diagnosis or you have inadvertantly switched off the stick trim
If the engine fails the max con check then industrial comp wash is next followed by further max con then governor adjustment - after that it is time to phone Rolls and talk replacements.