There are different levels of anti-user checks. Some only detect unlocked bootloader and/or root. Others use the play integrity anti-feature provided by Google. GrapheneOS tells you when apps request play integrity checks, and you'll see that a lot of apps do these requests constantly, even if they don't actually block you for using an unlocked or non-vendor system (custom key but otherwise locked and not rooted like GOS).

We really need a more foolproof technical solution for this if general purpose computing on the mobile phone is to be preserved. Perhaps some type of a remote control scheme to operate on a "slave" device. Failing that, if I do need one of such apps needing "strong" integrity, I'd probably look into getting an iPhone for those.