One of the things that I do teaching a new turbine pilot. If they are flying EDF's, I have the idle end point changed so that there is a constant low idle. Not enough to move the EDF on the ground. This simulates the turbine idle, just like you were trying to do with a delay. Besides the lag of a turbine, the other major areas of issue is proper airspeed control on final. Most new turbine pilots over shoot, because they aren't used to the idle. Another issue that I see is the turbine pilot flies it like a glow engine or EDF. What I mean by this, is the approach is high on final. Chop the power to idle, diving to the runway using the flaps as speed brakes, which they aren't!