After clicking on post-details of a user with e.g. >10000 posts the list of the ips the user also posted from gets so long and needs soo long to load that sometimes i get server time-outs or the browser task has to be killed.

So this feature is not useable for users which have many posts.
This list should be taken to an extra link on the post-details MCP screen.
And i would recommend a pagination for that list.
Best wishes.