That's very clever imo, really good out of the box thinking. The used battery idea is genius however in reality it is complex, there would have to be a separate power meter for each delegation you receive, if you have 10 to 20 unique users delegating to you, you will have all these separate power bars. It will increase complexity and processing on the blockchain, the current loophole is available to everyone even minnows so if everyone can do it, is it really that bad tho? The playing field is level at least, not like premining when only a few people had access to that.
My proposal would be to abolish the 4x increase in vote power to make post selfvoting less attractive. Keep the linear rewards though but I reckon adding the 4x power as well as linear was too much.