Hi Danny,
After ArchiCAD started (and called your add-on's CheckEnvironment and RegisterInterface functions), your add-on will be unloaded from the memory.
It won't work until the user try to use it, and at that point it will be loaded to the memory again and the Initialize function will be called.
So unfortunately it's not possible as far as I know.
I will try to figure out a workaround for that, but I can't promise anything now.
Regards,
Tibi