This document details the process to persist across sessions the information stored in the WebCache but the Enterprise Mode Site List capability in Edge.
Are you aware that UEM 9.2 already comes with a template that captures the Webcache? And since this is processed at logon and logoff the WebCache is not yet locked and can be imported and exported without issues.
Would not enabling DirectFlex solve the same issue for you, or am I missing something?
The Wininit\CacheTask process starts at logon. We were seeing access denied in the FlexEngine.log file when UEM attempted to import the WebCache, which lead us to believe the the CacheTask was already running by the time UEM was attempting to pull in the files.
If DirectFlex were to be used, the WebCache file would again be in use by the CacheTask process, resulting in UEM receiving access denied when bringing in the WebCache.