Nice. I now have a:

Linux nas3 5.15.14-200.fc35.aarch64 (NB. 14 instead of 13)

running headless and fully up to date wrt. dnf on the (presumably) newer build standard of rpi4 4GB.

The only oddity is that now the red LED that used to go off during booting now stays on permanently. Is that a deliberate change of policy?

:D