Being well prepared for a potential UFED extraction

In the coming months I will be traveling quite a bit via domestic flights within the USA. I would like to be well prepared, and mitigate the potential threat of a UFED extraction on my devices.

What is the likelihood I get stopped, and my devices seized when traveling domestically within the USA? Does it even happen when traveling domestically?

I will be traveling with an Apple Silicon MacBook and an iPhone. What settings in both devices should I enable/disable?

Is simply keeping both the MacBook and iPhone powered off, in a BFU state, with strong alphanumeric passwords and encryption enough to mitigate a potential UFED extraction via Cellebrite or any other UFED?

If my devices do end up getting seized will they be able to extract even encrypted data using the above method?

I also remember reading something about simply installing the Signal app will confuse a Cellebrite machine. Does this apply to iPhones/MacBooks? Does it work against other UFEDs? If so, how? Is it effective?

Any tips are welcome.