Android custom ROM with rooting support - eviltoast

So I’m interested in buying a Pixel 8 to install GrapheneOS in it but I’m also interested in rooting it and from what I’ve read rooting your device with a privacy focused custom ROM like GrapheneOS beats the purpose of installing it, so I don’t know if it’s actually posible to do it or if it actually has any grace, honestly I just want to be able to install some Xposed modules and be able to auto-update my Droid-ify apps in the backgrounds without user interaction.

Excuse my ignorance in the subject, I have never rooted or installed a custom rom before.