Not sure if it was a good purchase 🙅♀️
Active support and security patches will end on 19 Aug 2023 for Pixel 4.
Discussion
GrapheneOS does have production support for it, but I don't know if they'll maintain it longer than the mothership.
No OS can maintain a device beyond 'mothership' support.
They can provide a limited subset of security patches however once OEMs stop supporting devices firmware/driver updates then it is inevitable that they will remain insecure beyond then.
GrapheneOS provides harm reduction extended support releases where resources allow, usually up to the following major Android release beyond where OEM support ceases.
This is not full GrapheneOS and is ideally only to be used to provide transition time to a supported/recommended device or for people to flash on older hardware to get a taste/play around with the OS to see if it works for them on a daily driver production device.
This is great to know, I really wasn't certain how far past the stock Linux kernel they've built.
The kernel can be maintained, the issue isn't the open source elements it is the firmware/drivers for the hardware itself that are left vulnerable. Any device not recieving regular firmware/driver updates should ever be seen as secure.
You seem like the guy to ask about disabling IME or PSPP. 😂