There are vendors that sell the technology to adversarially access phone data, the "Before First Unlock" is the safest state a phone can be, but it's not infallible. The safest option is to have a burner or factory-reset phone with nothing on it, even if the hack succeeds.
Sad that we have to accept this as a risk of international travel, but here we are.
Morality and direct commonsense interpretations of law do not apply when there are literally unlimited resources stacked against you. But, assuming you can wait the potential ~10y to receive your device back that it will take to get your device returned to you, good on you. If you think that the current SCOTUS will rule in your favor, good on you.
The reality is, we live in a time where the most horrendous interpretation of the law is the one that will happen. And it won’t be in your favor.
The important wrinkle is that CBP’s published policy expressly guarantees that a person being admitted as a U.S. citizen won’t be denied entry solely because CBP couldn’t inspect the device. It doesn’t give lawful permanent resident (green card holders) that same explicit statement. Instead, it says refusal by a “foreign national” can be considered in an admissibility determination.