Question On the Impact Twin, can I monitor through the Compressor/EQ/Deesser, but without recording them, recording only the dry signal

Unfortunately not. The Compressor/EQ/Deesser DSP section is designed to work in close conjunction with the preamp and the 192 kHz / 24 bit converter -- together being the "Impact III" input stage -- in order to ensure optimum performance. Since these three parts form one unique recording channel, they cannot be split, and you always record what you hear.