> 5.1.3 An officer may conduct a basic search of an electronic device with or without suspicion, subject to the requirements and limitations provided herein and applicable law.

> 5.1.4 An officer may perform an advanced search of an electronic device only in instances in which there is reasonable suspicion of activity in violation of the laws enforced or administered by CBP or, in the absence of individualized reasonable suspicion when there is a national security concern.

In this climate, the qualifiers in 5.1.4 should be assumed to apply 100% of the time.

So, if you bring a device, be prepared to either unlock it and hand it over to be mirrored or abandon it and deal with whatever consequences fall out of that decision.

I'm probably never leaving this shithole again but, if I do, I'm coming and going empty-handed.

that's not your only options, but the ones likely everyone will follow. Guidance does not equal law.