Structures can become Invisible in Multiplayer Servers

Description:
Occasionally, when one player is working on an Estate while another player goes off and explore, the server can get into a state where it doesn't know how to make structures visible right away.
Exact Repro:
- Player A and B are working on a structure together
- B wanders away, while A keeps working on it
- When B is ~150m away, A adds resources, and then B gets a bit further
in detail: at this point the structure becomes non-dormant, and so distance-based relevancy becomes important, and B exceeds the relevancy distance while the structure is not dormant. this causes the structure to be removed from B's client. (normally dormancy prevents that)
- When B gets close to the structure again, the structure is re-sent to B's client, except the structure replication code doesn't think that the pieces are dirty so it skips them

State:
Actively being worked on

Workarounds:
- Both players need to log out, wait 15 minutes, then log in again

To help the Development Team with this issue:
Nothing at this Time