Hi all, Lenovo released a new UEFI update for the Lenovo X13/T14s, changelog is here: https://download.lenovo.com/pccbbs/mobiles/r1cuj63wd.txt
It lists "Fixed an issue that Fixed TSC synchronization failed under linux." as a fix, I can confirm after removing the tsc=unstable CMDLINE everything is functioning perfectly. The bottom of this issue was indeed Lenovo's shotty firmware. Thank you to everyone.
