More info: Review of recently recieved A04
On shutdown, framebuffer error prints on screen error 1b_set_par error, error code -16. Userspace programs (often) fail to spawn properly (probably related) and can not be killed by both user and root. The programs being affected the most are firefox and other GeckoMain-based web browsers. systemd-shutdown fails to kill same processes on shutdown, leading to hung shutdown. Error is not SystemD-related as initially suspected.
dmesg | tail produces sun8i-ce 1904000.crypto: Fallback for cbc-aes-sun8i-ce is cbc-aes-ce repeated ad infinium. Possibly related.