A universal X-Legend launcher patcher that allows downloading from your own custom server.
This only patches the launcher to allow patch files to be downloaded from your server and does not include tools to create said patch files.
There is also a bug in the launcher implementation where it doesn't escape url strings with a hastag (#) in them, and will fail to download them. This is of course out of my control and is entirely on X-Legend's end.
Without the actual source code of their launcher it is impossible to exceed certain limititations like the length of urls and log name.
The base code and release support the latest TW and HK launchers of Aura Kingdom/Fantasy Frontier as of October 2 2021, and you can add support for more launchers down the line using the json files inside the Config folder as template. If unsure, check the source code for the implementation.
I am in no way affiliated with X-Legend.