thinkpad-ec

That is the general nature of reverse engineering efforts, but this one has been documented enough that you don't need to blindly trust completely random executables or code from strange places. You can manually recreate the process of building a patch for the embedded controller instead of just following instructions: https://github.com/hamishcoleman/thinkpad-ec. Here's the presentation by the author himself at linux.conf.au (what used to be the biggest local Linux conference for those of us in Australia and NZ): https://www.youtube.com/watch?v=Fzmm87oVQ6c. This is of course not supported by Lenovo. Unlocking the BIOS is definitely more like what you described. It's the price to pay for freely playing around with processor power limits, getting AES-NI instruction set support, etc. I have not checked since 2019, so there might be a cleare

The x220 battery definitely works with the x230 but requires the DRM patch. I'm running an x230 mainboard in what is otherwise an x220. It's an EC not BIOS path so should work with coreboot. Files at https://github.com/hamishcoleman/thinkpad-ec While swapping cells, just be careful to match voltage and severely limit current to avoid any danger/excitement. Sure you can find some forum posts on this. Also, the new and old cells must be brought very close in voltage as discrepancies are flagged disabling the battery. This also goes for between cells but allowable differences are larger. I think this battery has 3s3p configuration. I've bought quality 18650 cells online 10 for about $100CAD for a x220 battery rebuild. More recently got 2x 2Ah 18v Ryobi packs which yeilded 10x cells total for $29CAD on clearance at Home Depot....

You can also mod an X230 or a T430 with a xx20 keyboard, which is worth it as the CPU/GPU and USB ports are all a decent upgrade. You need to flash the embedded controller though, to remap the keys - also worth it, to use a third-party battery. The process is not too difficult, you just need to compile the stuff, make a bootable flash drive, and boot from it - no soldering etc. https://github.com/hamishcoleman/thinkpad-ec

Ooh, this is interestingly relevant to me.. I've bought a bunch of X230's and X230T's recently, all of which have genuine batteries. I imagine a time when the genuine batteries are no longer produced/sold. Luckily it does seem there's a tool to allow using non-genuine batteries at https://github.com/hamishcoleman/thinkpad-ec

Unless you strongly prefer the smaller form factor, I would suggest T530 (the intel igpu version, not the nvidia one) instead of x230. T530 supports FHD natively. The keyboard mod principles are the same for all laptops from that year. Keyboard mod resource: https://github.com/hamishcoleman/thinkpad-ec x230 FHD resource: https://forum.thinkpads.com/viewtopic.php?t=122640

You can 'fix' that at least: https://github.com/hamishcoleman/thinkpad-ec

it would with coreboot https://www.reddit.com/r/thinkpad/comments/5p3mpm/how_to_fla... + https://github.com/hamishcoleman/thinkpad-ec for EC sourcecode besides Allwinner A64 = tons of binary blobs, often containing gpled code and openly violating open source licenses