It may be possible to get past that, I’ve seen people disassembling the battery to get the BMC and connecting the DC power supply to that instead.

It sounds way more risky than OP’s initial idea. I wouldn’t recommend taking apart batteries.

I think they are wondering if one extension can use both v2 and v3 APIs at once? As in whether v3 APIs will be “backported” to allow v2 extensions to use them

I don’t think I have enough knowledge to solve this or say anything for certain, but I wonder if the power button is treated as an external keyboard and is getting ignored in tablet mode?

Regarding your mouse double clicking, some Reddit users suggest pressing the click button quite hard a few times…