upon getting the mining gadget and an energy upgrade, put the upgrade in the tool and notice how you get a slight bit of free energy. i assume this is intentional

but the bug comes when you remove and intert the upgrade. each time the upgrade is added the free energy is re-added

so if you have a tier 3 battery upgrade (which is what i tested with and found the bug with) and inset it, each time you get 1,500RF free, so if you take it out and put it in 4 times you get 6,000 free RF

Haha, this is great. The reason it does this is to avoid an issue where the gadget would be stuck on the last upgrade battery. Say you had a tier 3 and put a tier 2 in, you'd still have 10m in the gadget so we've pushed a small update. I think the simplest way to sort this is to figure out why the simulate var didn't work or just put the insert to 1rf making it pointless to do this as it would take a million clicks yet to fill tier one :P