If player disconnects inbetween seemless travel, will OnPostLogin and OnLogout still trigger as no GM?

In Unreal Engine 5, I’m managing player data, such as usernames and other details, within the server’s game instance using blueprints and replication. This process has led me to an intriguing question related to player disconnections during level transitions.

I understand that in the Game Mode, there’s an ‘On Logout’ event that identifies the player controller (PC) when they disconnect. My query focuses on the scenario during level transitions with seamless travel. During these transitions, the Game Mode is briefly destroyed and then recreated for the new level. I’m curious: is there a possibility that a player might disconnect in this short interval, thus bypassing detection by the Game Mode and preventing the ‘On Logout’ event from triggering? Furthermore, are such disconnects tracked and stored until the new Game Mode instance is active, to ensure appropriate actions are taken once it’s operational?

Additionally, I’m considering whether it’s a common practice to rebuild the entire player info list when entering another level. My concern is that this could lead to unnecessary network traffic. I’m interested in understanding the best practices for managing player data across level transitions to optimize both performance and network efficiency.

PlayerControllers are not destroyed during seamless travel.
A replacement PlayerController is spawned if the next level is using a different Class PlayerController though.
Logout should be reliable even if it happened during travel as the server would destroy the PlayerController when the client has disappeared.

If it is pure data then keeping an Actor alive with the data would be a lot easier using the SeamlessTravelActorList however if it is an Actor with a lot of runtime object references it is probably best to respawn it in the next level to reinitialize everything.