I've upgraded a flashed 5.1.011 image to version 5.1.019 via opkg upgrade and ran out of flash space.
Upgrading package openvix-enigma2 installs some skins (openvix-magic-fhd, openvix-youvix-blue) which I don't need and upgrading package kernel-vmlinux writes a kernel-image to /boot on rootfs (for whatever reason).