Short description of error
In order to make a progress bar, the value needs to change over time according to loaded data.
LibLoad status progress only outputs 0.0 and then 1.0 when the lib is loaded.
There is no progress at all such as : 0.0 0.1 0.2 0.3 0.4 0.5 0.6 0.7 0.8 0.9 1.0.
status = bge.logic.LibLoad('//xxx.blend', 'Scene', async=True, load_actions=True, load_scripts=True)
storing the status in some global object, then accessing it from another logic brick while the game is running.