Would it be that bad if it were a persistent check that happened on boot? All you'd need to do to validate the hardware in your phone is reboot it and it would barely have any impact during normal operation.
I don't know. Maybe a few weeks ago. The point of doing it on boot is that if you're so important that your threat model includes avoiding non-certified parts, you have an on-demand check to validate the entire chain of hardware in your device.
So if you take your phone in for a repair, reboot it afterwards to make sure the parts are all certified. After that you don't need to do it again unless you leave your phone unattended or have a reason to suspect someone swapped parts on you. There could even be an option to toggle on super persistent warnings if needed.
The point is, you don't need persistent warnings to give a normal user the tools they need to check if they have all genuine parts. Reboot your phone after a repair to ensure you received genuine parts is a pretty simple concept to teach people.