This can be most easily seen if you have Draconic Evolution installed and have access to its Energy Transfuser or Generator.
To reproduce,

1. Give yourself an Energy Transfuser and Generator:
   give @s draconicevolution:energy_transfuser
give @s draconicevolution:generator
2. Give yourself an Infinity Tool without any energy.
3. Place the Infinity Tool in the Energy Transfuser.
4. Notice that its capacity is reported as -1.
5. Place the Infinity Tool in the Generator.
6. Notice that it loses 1 FE/t.
7. Notice that when the energy level in the Infinity tool hits 0, it decrements once more to -1 while simultaneously powering up to Artifact tier.

This is important because that exploit allows players to get Artifact-level Infinity Tools without having to invest the 9.223 quintillion FE required to reach that level.

One fix would be to have the tool report a capacity of 2**63-1 (the aforementioned 9.223 quintillion) instead of -1.

Industrial Foregoing Version: 3.2.14.7

Titanium Version: 3.2.8.7

Draconic Evolution Version: 3.0.18.428

Mod Pack: FTB Oceanblock 1.11.0

I made an infinity drill on my server, got it to 5x5 size before I ran out of power, went mining and then the power amount instead of stopping at 0, went into minus and now I ended up with the 13x13x13 drill. Tested twice more and it just switches as soon as it reaches minus which it shouldn't even do.

After a bit of testing I have realised it is unbreaking doing it. If it has unbreaking on, it glitches when used up. I suggest disabling unbreaking for the drill