I'd like to add that I'm not really conscious of the phone misbehaviors. If I knew they were malicious, I would take my devices to authorities or security consultants or whatnot, but I can't tell if I'm imagining them or not because I have amnesia around the intermittent things, neurologic issues that make similar experiences, and bad confusing flashbacks prevent investigation and verification.

One of my big goals is having and using a device that behaves reliably. So hashed backups of working firmware, and a norm of reverting to them, would be a great step.

I'm guessing that OpenKeychain won't stimulate frequent popups if I build it from source rather than downloading a binary.