Giving it back based on being alive on Dec 31 seems the best solution to me. (It’s very difficult to game and if you give 900 billionaires under a million bucks in total, it’s just not that big a deal…)
We manage to phase out ACA subsidies at 400% of the federal poverty level, so I don't see why we couldn't use a similar mechanism for an energy tax credit.
You can. It will cost political capital and erode the clarity of the messaging about the purpose of the tax. It also gives politicians one more thing to dick around with later.
Personally, I think it’s letting the perfect be the enemy of the 99+% perfect.