In ATP Regen, the pegging file is to support the ATP inquiry drill down to pegging (F7 Key), or printing of pegging report. Pegging information may be valuable for planner. But most of the people do not use Pegging information.

During ATP regen, it automatically regenerate pegging information and can be time consuming. If you do not use pegging data, then there should be an option to disable the regeneration of pegging. It is suggest that we add a flag in Global Setup -> System -> Available to Promise:
38. Create Pegging Data During ATP Regen? Y/N
Default "Y" to match current behavior.

If this flag is set to "N", then the F7=Pegging drill down option in ATP inquiry should be disabled. Also, the IM -> Reports -> Available to Promise Report -> Available to Promise Pegging Report, should be disabled (popup with message) when user choose it.

Lastly, during ATP regen, system will attempt to create pegging data and the benefit is to speed up ATP regen. Pegging regen can take significant amount of time.