please remember, any infomation about power should be combined with attention to linearity. One can watch the transmit Signal with the Pluto itself. Use a dummy load and/or directional couplers with the right attenuation and look to the spectrum. The Console in combination with the Pluto gives a rather clean two tone signal with 0dBm PEP. This all is possible without a spectrum analyzer.
At least the transponder will show if the transmitted signal is ok. From my point of view there is a great general improvement compared to the beginning more than a year ago. Don't forget the equalizer and the compressor.
The goal must be to find a transmitter chain without unneccessary intermodulation. The Pluto followed by the CN0417 delivers +20dBm
(100mW) with good linearity.
@Oliver: Why don't you stick all the attenuators together and place it behind the last amp? With 36dB of gain of a two tone signal there is no danger for the attenuators. From 0 dBm of the Pluto you achieve 36dBm PEP (4 Watts PEP), the 2 W dummy load will withstand it keeping the transmission short. I would try to bring an damped signal back to the receiver to control intermodulation.