We investigated the application performance. Based on analysis of profiler results following optimizations were done:
1) For CFieldValue and ItemFieldSettings entities unneeded entity refresh was skipped.
2) Fixed N+1 issue for Formula entity and found several other places where N+1 issue exists
3) Optimized CollectItemFieldSettingsByItemIds method which execution was quite expensive during scenario execution.
Those changes increased performance of the tested scenario by 45%.