Definitely agree that HW is a tougher ask. Though I mostly see it as an engineering problem that hasn't been solved mainly because no one is really trying. And

Definitely agree that HW is a tougher ask. Though I mostly see it as an engineering problem that hasn't been solved mainly because no one is really trying. And apparently rechargable button cells do exist based on a quick google search, though i have no idea how widely available they are. But again, it's just an engineering problem that can be solved should the right people put their minds to it. I can't really design hardware, but I did write the firmware for a two man startup at one point, designing custom electronics for people with too much money. We always made the source available to the customer and made our stuff USB or JTAG programmable. Not that any of them actually cared, but we did!