Loloverde-
Per the firmware documentation:
Hold down Setup and touch anywhere in the Inputs or Mix meter tab to set the associated source point. This will affect the Surface LED meters too. Options available for Inputs are Post Trim, Post Gate/PEQ, Post Compressor, Post Delay. Options available for Mixes are Post Trim, Post Insert Return, Post PEQ, Post GEQ, Post Compressor, Post Fader.
Post Fader on inputs is NOT an option through v1.8x.