Disclaimer, I don't use GrapheneOS. But I did mess around with multi-users on Motorola Phones.

I'd recommend having a bunch of decoy stuff, you know, non-political stuff, on the main profile, and have your anti-government activities on the second profile. This way, if you see cops following you, you can delete the second profile (I hope you have frequent backups btw), then if the cops ask to see your phone, you could show them your totally innocent main profile.

(not saying you should show them your phone, but it is an option if you wanna, say, cross a border)

Maximum paranoia.

The main profile should be very vanilla.

Use a secondary profile as your daily driver, play with the cross profile notifications

Use different logins for the main profile and secondary profiles.

I'd lean toward the way you have it now. I like having the owner profile as my daily driver. Any app that I have doubts about gets its own profile.

If you haven't already, check out the Graphene forum and search for profiles. There have been lots of discussions about this, and you'll find some good examples for various privacy/security needs.

Unless you have a reason to, I wouldn't recommend a secondary profile as a daily driver yet. SMS doesn't work perfectly and plenty of other bugs I've noticed which sometimes you have to switch to the Owner profile to access certain things, and sometimes things just don't work in secondary profiles.

That being said, I've made it work. If you have a reason to use this threat model then do it.

It depends on what you're trying to achieve.