PixelFarm has a lot of goals and a lot of work to do. It should be reduced.

I have searched many graphics libraries and font libraries.
But most of them are just wrappers of C libraries. For example SkiaSharp, HarfBuzzSharp, etc.
But C# never has its own graphics library, even the port is also much better than wapper.
Your project is the hope of .net.
This is a great thing.

But PixelFarm does too much.Such a huge goal would be difficult to achieve without large-scale investment from large companies.
Therefore,the project should be subdivided again.

It is enough to make PixelFarm a pure 2D rendering, font rendering, and text typesetting.
It can even be further divided into:
PixelFarm.2D (replaces SkiaSharp) //Focus on soft rendering first. Don't try to connect to hardware acceleration.
PixelFarm.Font (replaces FreeType, HarfBuzz, ICU or FriBidi)

some Reference maybe will be little help :

https://github.com/fsufyan/BidiSharp This may pure C# ,not a wapper.
https://github.com/libass/libass
https://github.com/harfbuzz/harfbuzz
https://github.com/salshaaban/BidiRenderer
https://github.com/Tehreer/SheenBidi
https://github.com/fribidi/fribidi

https://github.com/Robmaister/SharpFont.HarfBuzz
https://github.com/ammariqais/SkiaForUnity
https://github.com/TJYSunset/HardFuzz
https://github.com/VassiliYakovlev/SkiaHarfbuzz
https://github.com/mono/SkiaSharp/tree/main/binding/HarfBuzzSharp
https://github.com/mikernet/Uno.HarfBuzz

https://github.com/Robmaister/SharpFont
https://github.com/ryancheung/FreeTypeSharp
https://github.com/MonoGame/MonoGame.Library.FreeType
https://github.com/fumifumi0453/SimpleFreeTypeSharp
https://github.com/tonisimakov99/FreeTypeBinding

https://github.com/vidstige/NRasterizer
https://github.com/MikePopoloski/SharpFont
https://github.com/MatterHackers/agg-sharp
https://github.com/NewWheelTech/geometry4Sharp
https://github.com/PaintLab/PixelFarm
https://github.com/PaintLab/poly2tri-cs
https://github.com/MaulingMonkey/poly2tri-cs

https://github.com/bp2008/BetterClearTypeTuner
https://github.com/character-map-uwp/Character-Map-UWP
https://github.com/LayoutFarm/Typography
https://github.com/SixLabors/Fonts
https://github.com/FontStashSharp/FontStashSharp
https://github.com/imkira/unity-sysfont

https://github.com/opcon/QuickFont

https://github.com/roy-t/MSDF

https://github.com/Rungee/NLineBreak
https://github.com/ufcpp/GraphemeSplitter
https://github.com/DaniRK/UnicodeScriptDetectorNet

https://github.com/pgrit/EfficiencyAwareMIS
https://github.com/pgrit/MisForCorrelatedBidir
https://github.com/pgrit/SeeSharp