TOPIC:

Got an Icom 705 which I would like to use on my system , I, e through the antenna switch genius 8/2 , and also connecting to the power xl amp.

As far as I can see, you cannot use any kind of automatic control of neither AG, nor PGXL. Only manual.
Unless you provide BCD (for Antenna Genius) or CI-V (for both AG and PGXL) information, if available, from IC-705's micro USB connector.