I use FT8 and there has been discussion about what ALC settings are best when using this mode with the G90. I found recommendations in groups.io on the Xiegu G90 group that says after 1.78b, the ALC settings reversed and now 100% means zero (0) input whereas 0% means max volume. The video shows this. I have found the output to be good if the ALC is between 20% and 80%. The video below attempts to show the relationship between volume and ALC.