Sadly GrapheneOS is only available on recent Pixel devices. I know I'm probably the only one that still cares about these features, but I won't buy a phone that requires me to hot-glue a USB dock to it just to get 3.5mm and microSD if I can simply buy a Sony instead :/
Set it sufficiently low, and it's a pretty good option to ensure keys are evicted and if you use a SIM pin, it's even better.