That would be a good compromise.
I am not into FPGAs, so i ask you: is it easy to verify there aren't suspicious components in there?

For motherboards  it is not easy to check.
See https://tech.slashdot.org/story/17/11/07/1041236/minix-intels-hidden-in-chip-operating-system
or https://itsfoss.com/fact-intel-minix-case/

Or even for CPU cores: https://www.tomshardware.com/news/x86-hidden-god-mode,37582.html