12.2.4 - Inventory Period Close Performance issue

Hi, We are upgrading from 12.0.6 to 12.2.4 and we are seeing a severe performance degradation, thereby by negatively impacting the period close process. We are working on an SR and we were provided a couple of workarounds and neither seem acceptable for our management. We have about 80 orgs and the process completes anywhere b/w 5-20 mins in 12.0.6 whereas the process runs forever and never completes in 12.2.4. The workarounds provided are

1. Delete the stats for a handful of tables. This improves performance. However, these table are used by a bunch of other process and we don't even have a definitive list.