We have resently started an initiative for meta-mortsgna and ”related” layers, where the initial aim is to have it building to some extent, first for kirkstone, and later for scarthgap.
And in the meantime also evaluate this ”eco-system” and also possibly make it more ”layerindex friendly”, e.g. for using layerindex-fetch.
Inspiring Best Practices in Yocto and OE Ecosystem