Re-exporting EAR99 software with encryption from Singapore: de minimis sanity check

Our product bundles a US-origin encryption library (ENC-restricted, 5D992 self-classified) into otherwise non-US software. Before we re-export from Singapore to a customer in an E:1-adjacent market: does anyone have a worked de minimis calculation for software where the US content is a linked library rather than source? My percentages feel hand-wavy.