Resizing the Message scrollback length

Now, if I change the size from 1000 to 50, the message scroll in all chats will decrease to 50. But if I do the same thing from 50 to 1000, then the messages will appear after restarting the app.
If this is not planned, it needs to be fixed. If this is planned, there should be a pop-up "DankChat needs to be restarted to apply the settings [Restart]".