In the ship design screen, "All Must Tithe" says it adds +15 Dust per module.  However, when you mouse over your system's Dust income at the start of the game, it seems to only add +10.

Also, if you add All Must Tithe modules to your Ark in ship design, then upgrade it (and unanchor & re-anchor your Ark), it does seem to add only +10 per module instead of +15.

Not sure if it was intended to add +10 or +15, but it seems like the module description should match what it actually does.