Right, these goons are hand searching through phones specifically to find something, anything, they can use to make your life suck and detain you further.

A pin that boots into a dummy account, full of benign messages, photos, innocent web browsing, etc. is going to get you a pass. They'll flip through everything and get bored after a minute of not finding anything.

Far less likely to aggravate them than wiping your phone

They would learn about it and it would be standard practice when they see pixels.

It's not possible unfortunately due to low level SSD architecture[1] and other reasons:

https://nitter.net/GrapheneOS/status/2082153517234676150#m

[1] https://veracrypt.io/en/Trim%20Operation.html

https://veracrypt.io/en/Wear-Leveling.html