Hi,
Yes, this is possible, you don't need to grant SharePoint access to your validators. Instead:
1. Set up a dedicated service/batch user with SharePoint access to the ER destination.
2. In D365FO, go to System administration → Setup → Batch group (or use an existing one dedicated to this job), and configure that batch group to run under the service account's credentials.
3. Assign the posting/ER batch task to run under that batch group instead of the user's own session — this way, the batch job executes as the service account, not the person who triggered posting.
4. Since your ER job is currently showing batch job "0" (meaning it's not actually queued as batch, likely running inline), double-check your posting profile/workflow is set to "Batch processing = Yes" so it truly routes through the batch framework using the assigned batch group/account, rather than running synchronously under the current user.
This keeps the SharePoint write happening under the service account, while your validators only need standard D365FO access to post
Thanks