lobby_panels.xml split can be reverted to lobby.xml and be merged back into lobby.xml, as this patch uses style parameters in js to set lobby to dialog and normal window.
fullscreen ingame/gamesetup overlayed lobby (as pushed gui, no join button, no host button):
having lobby available in-game and in game-setup (and maybe in end-game summary) as overlay
shortcut hotkey should be configured ("Alt+L") globaly
if dialoged desired: (but that needs massive xml code moving)