Hi, @achim. If you have a gimbal controller that supports SBUS, you are at luck. Then you just needs to make a splitter cable from the SBUS receiver to the F3FC and the gimbal controller. I have done so with luck from my X4R-SB to my STorM32 (NT) BGC. The way i made my splitter cable is so that all 3 wires (signal, ground an plus goes between the receiver and the F3FC board, while only (and this is important!) ground and signal wire goes from the receiver to the STorM32 board. In the F3FC I selected the lower 8-10 channels, while in the STorM32 BGC selected the channels from 11-16 for control of the gimbal.
This way you will not need any AUX pass through on the F3FC and as such you will save ports for other cool stuff;-)