Hey Riewest, thanks for reporting this in. Me and All_under_heaven were suffering from the same issue, as you pointed out, its a java process that is just eating ram and processor power, that process actually is the minecraft launcher thats being a derp. Even if you tell it to close after you launch, it still does that, as far as we know its nothing we can fix on our end. The known fixes, as you said, are either closing the process manually on task manager, or, maybe using another launcher, although we didn't test that yet.