In other words:
How can AGC table be extended to slave GPO3 and GPO2 control pins besides GPO0 and GPO1 pins used with a control bit in the table for extLNA of each RX1 and RX2, respectively to slave one more extLNA together with the given extLNA for each RX1 and RX2?
Datasheet References: When using external LNAs, AD9361 can optionally slave GPO_0 and GPO_1 off the receive gain tables to control LNA gain on each of the receivers.
Briefly, a bit in the gain table can be output of a GPO and used to control the gain of external LNA.
Reference: Gain table in conjunction with an AD9361 GPO controls the external LNA. A bit in the gain table drives GPO0 for RX1 and GPO1 for RX2. Setting this pin zero results in a low GPO output level while one results in a high GPO output level.