Thank you for anwering!
I know, N1 below 1000 feet is an non-stabilized situation. So are excessiv sink rate also, I use to take this into consideration also.
I will check what happend in the NGX when turning on TAI or extending landing gear and watch N1 indications closely. Some of the most hard core simmers who also really care about problems like this, told me it could be an FSX limitation, which leads to mandatory thrust leaver movement by the AP for simulating new ground idle. It would be strange if this really is necesary but I really dont know the limitations of the program codes.
By the way, 60 tonns, flap 40, approach speed at VREF+5 lead to 59 % N1 for maintaining speed and 2.5 degrees g/p! I think the engines and model is awesome modelled, something totally other than the old PMDG, which many pilots know about : )