Since this thread was 4a and I was thinking of installing GOS but with certain kernel upgrades caused lot more issues and being on latest doesn't mean it's secure.You could do a major step forward in terms of security and privacy of your Google Pixel device by installing GrapheneOS which significantly hardens many security aspects: GrapheneOS features overview
As long as the Pixel receives Security updates i see no reason for him to go to custom Rom, since with a custom Rom, most banking apps will not work anymore because of the unlocked bootloader.You could do a major step forward in terms of security and privacy of your Google Pixel device by installing GrapheneOS which significantly hardens many security aspects: GrapheneOS features overview