The Titan security chip is not a black box. The Titan M1 gas been scrutinazed by blackhat: https://dl.acm.org/doi/fullHtml/10.1145/3503921.3503922

Just because something is not open source does not mean you can’t verify it (no, i’m not shilling closed slurce; no i don’t think closed > open; no i don’t think closed source is more secure)

GrapheneOS!

Hi! I know this option doesn’t respect the second point of your list. That beijg said, if i was you i would buy a Google Pixel 7 or 8 and then i would put GrapheneOS on it!