Hi Jajah
The default is user-specific.
Why would you need to lock that down? If you do that you are taking functionality away from the users.
If you don't grant S_ALV_LAYO to the user then they cannot change default for the report.The user can go into and manage their variants to remove default.
What is the risk in a user creating their own default?
Without seeing the context of what SAP said, that object is all about globally maintaining a layout and publishing it so it's available to all users. Users can still come in and make the choice.
A possible way to lock it down is to grant F_IT_ALV with ACTVT 03. However, this will mean users cannot save their own variants and must use the global display variants. This could frustrate users who access reports frequently and build their own variants (it would apply to all the ALVs).
Regards
Colleen