Hi,
AFAIK, there's no hardcoded limit for a Lookout process filesize. However, it can be reasonably expected that its load time will increase with size.
I strongly recommend you consider breaking up your process into multiple process files -- one (or more) Server process, and the rest Client processes (based on some modular design). This will definitely pay off in the long run. This way, you can also load and unload selected processes using the Loader Object.
Regards,
Khalid