It'll usually be listed in the BIOS upgrade guide. I've only ever seen the "weird recovery methods" on more performance-oriented mainboards - your RGB-heavy "gamer" boards tend to have some sort of recovery method. I don't know of any major OEMs who have such a thing. For a Thinkpad, though, I would wager good money that someone has directions out there for how to do it with a SPI flash clip - BIOS modding Thinkpads is pretty common, and most of the more intensive mods can't be done without an external writer.