You don’t seem to know much about modern electronics or forensics. “Probing” the “circuitry” isn’t going to get you anything. The devices supported by GrapheneOS keep their encryption secrets in tiny, sealed chips that are strongly tamper-resistant and will erase themselves if you attempt to get to the actual memory cells without specialty equipment. The only labs that can extract information from chips like this are very rare, expensive, and slow, and success still isn’t guaranteed. Plus these labs are going to have a backlog of espionage and military cases; they aren’t going to be working on some random dude’s phone unless he’s a cartel boss.