On the N1 governing by the DECU - with AC talking about matching N1 or Tq - I think that is confusing the ability to beep the engines up and down to match them in the way you prefer with what the DECU is designed to do (govern N1 and load share with the other engine)
DECUs, and any governing system, only govern N1/Ng when the engine(s) are at idle. With the Nr in the normal operating range they govern N2/Nf. Matching N1 is something different.