I’m sure this is working for you, and it may be distro specific, but for me I did not have to do this. I have seen two ways of omitting something in grub: module.blacklist=yes and modprobe.blacklist=module, also https://forum.chrultrabook.com/t/lenovo-c13-yoga-nvme-disappears-on-reboot/1196/5?u=brisk.rain this post solves the problem in the same way you did but on pop os, and uses underscores. So I’ve been putting all 4 versions in my grub.conf, and it seems to be working fine on Fedora. So I have:
cros-ec-uart.blacklist=yes modprobe.blacklist=cros-ec-uart cros_ec_uart.blacklist=yes modprobe.blacklist=cros_ec_uart iommu=pt
3 of those may well be unnecessary, but I’m not going to figure out which until it stops working.