Since I wasn't able to fix the actual HwComposer, I ended up coding my own.
Right now, it just loads itself and performs some operations, but it isn't fully functional.
It should load fine on any Huawei/Honor recent device.
I checked out Benjamin Gaignard's DRM HwComposer and also the CodeAurora's one, however, I coded it from scratch.
If you want to include it in your rom, I'd appreciate it if you could post a link somewhere to this document.
As always, if you are familiar with C++ and want to collaborate that's perfectly fine!