Openpli has now branch sumo, thud and zeus.
I think sumo is dead and zeus can been easy update to long term support branch dunfell. ( https://wiki.yoctoproject.org/wiki/Releases )
The preparation in all the previous branches seems to make it possible that the step to dunfell is low.
I made a git with dunfell which can been used as start: https://github.com/wte-chromium/openpli-oe-core/tree/dunfell
The only packages which fails by me is djmount. The AM_LANGINFO_CODESET fails. It's something with iconv and m4 but I do not know what a clean patch or solution is.
I found the follow patch which seems to work but I think this is more a workaround for the problem: https://github.com/OpenVisionE2/openvision-development-platform/commit/ba84fb3370a6969c0691cf40404aaa48843c4115
