Sysupgrade on squashfs raspberry pi 4 doesn't clear overlay

What would be the recommended way to run OpenWRT on RaspberryPi then? Should I just use the ext4 images?

Since I already experienced broken ext4 partitions on long-running Pis I hoped that using the squashfs images would be more reliable, but reading the linked thread makes me question the reliability of f2fs and the squashfs images for RaspberryPi in general.