I switched to Graphene on my Pixel 9a Pro, I don't know, maybe a month ago. It's, as the title says, almost perfect. However, I'm having two issues:
Android Auto
-- From what I've looked up, this should work. It does if I wire it up, but wireless is supposed to work also. I thought this was due to my VPN, but I've tried with Auto allowed through and even with the VPN (and kill switch) disabled. With the VPN on - passthrough or no - Auto just tells me to disable my VPN. With it and the kill switch off, it just says that it failed to connect. It's been a while since I tried it with the kill switch on, but I think I remember it trying to connect to some oddly named Wi-Fi network offered by the car. This did not work. edit: Essentially the same result has been encountered in two different cars. I did try toggling the developer settings with no impact. I was able to get Bluetooth working.
Okta MFA. I don't think this is a Graphene issue because I also put Graphene on my tablet and it works fine there, with or without a VPN. However, on my phone, if I try to add the account it just says some form of "there was an error, please contact your administrator." My administrator has no interest in troubleshooting this.