Is that what you are saying? Can you walk me through your logic because it's escaping me.
Objectively, it is a risky process to do without the right tools based on feedback from people who have actually done it on a regular basis; ref. the poster upthread here: https://news.ycombinator.com/item?id=31457776
It's unnecessarily annoying and admin-heavy. Compare that to just buying a handful of batteries and keeping them "just in case" so you can then do the repair in your own time as needed. I currently do that but have to use grey-market parts as Apple won't sell them to me without the aforementioned restrictions.
Returning cores for a price rebate is a totally standard industry practice. You apparently get 18 days to initiate the return and Apple gives you a free return label.
> Returning cores for a price rebate is a totally standard industry practice.
Depends for what. A worn down (or outright destroyed, if you screwed up and couldn't get it out intact) battery has zero value beyond its raw materials, which are much less than the cost of shipping it back (the eco-friendly option here is to drop it off at a local recycler which will collect and ship them in bulk).