The Insulation Contractors Association of America’s Technical Bulletin 27: Applying Batt Insulation Above Suspended Ceilings to Meet Code addresses and recommends practices known to conform to the requirements of the International Building Code and to all three model building codes.
This is the question you must pose to yourself: What is the return on investment (ROI)? You and your people to whom you have delegated production responsibilities should ask this question routinely.