Within a D365 DataVerse environment it's possible to include system user records within standard activities records, e.g. emails, phone calls and appointments. However, the system user Activity 'Timeline' doesn't display related activity records, as the Contact and Account entities do. This is because activities cannot be enabled for the 'System User' entity, by design.
We have implemented a stakeholder management solution for a client recently and this is a serious limitation for them. A key part of their stakeholder engagement is with system users.

We ask that Microsoft allow organisations to enable 'Activities' for the standard 'System User' entity.