@kesson I don’t know a lot about how the Processing mode is using HotSwap but I can guess some problems. Can you be more specific about library and how you’re trying to initialize it?
The library will at least have to be installed beforehand, assuming the mode doesn’t provide a custom classloader that allows for this.
The major limitation of not being able to add fields or rerun setup() could be a problem. I can think of a few hacky workarounds, but not without knowing the specific library and initialization you need.
PraxisLIVE works around all the above issues btw 