Yeah so far I haven't found a way because the script demands the actual launcher to be downloaded every time you run it, because it is stored in a temporary folder.
Am I able to run the different modpacks when I'm offline? I've looked at the code and as far as I'm aware of I have to be online for it to work, because the workflow demands the .jar file to be downloaded every single time I run it.
Any help would be much appreciated.