I understand that some Lenovo laptops have a white list for approved PCI-Express cards, is there a way to circumvent this on the x230 with a BIOS that doesn't implement the whitelist? There is a forum to request the modification but it's now like 334 pages long.
It's possible, but it requires a bit of hardware hacking and is fairly difficult. You can find the instructions here. You have to have an eeprom programmer, and reasonable solder skills.
That said, you can find a petition to Lenovo to stop imposing whitelists to achieve vendor lockin. Please join in combating this restrictive practice.