I can help shed light on this issue and the general workings of the OSOT Fling. The OSOT implements its settings in four specific areas.
OSOT Target Locations
- Local Policy
- HKLM - Reg for Local Machine
- HKCU - Reg for Current User
- HKCU (Default User Hive)
First, note number 4. The OSOT does not simply enable local policy or create registry keys. It targets every location relevant to the setting. Add to the fact that changing the group policy setting does not remove the entry in the default user hive and you have a reoccurring issue without obvious solution.
The second and most crucial item is the OSOT never stops at simply targeting the specific policy setting to enable/disable. It targets the feature and any related settings to that feature. If you re-enabled the feature, it will often not be at full functionality. This is a thorough approach but makes reversing challenging.
In the case of the Thumbnails, enabling or deleting the disable reg key is not enough. Root cause is the Thumbnail feature can't function if it can't cache the created thumbnails to the thumbs.db. See attachment for details and once removed from Default User Reg Hive, it will stop regenerating.
