I’m familiar with the news about the brick - in the past I’ve had this problem (I think it was a bricked… pixel 2?) and faced similar power off issues. Keep trying what you’re trying but in various ways - I vaguely recall that I had to press volume up first and then hold power or something like that (meaning pressing them both at once or power first didn’t work). One of the various combos you’re trying is supposed to be the one that forces it off after ~30secs of holding but a fuzzy memory reminds me it was real finicky to actually get working. Worst case scenario, just let the battery die. :(