The project is Apache2.0 license, so we can use their code.
But this looks to be MS-Windows Only (C#, Visual Studio), there is always Mono, but even in that case it probably requires porting effort and wouldn’t be a library you could drop into Blender.
So any integration would likely be separate applications communicating, rather then directly integrating libraries.
Its possible to integrate Mono into Blender using their C bindings, then we could run C# code, so… in principle code could be integrated, but this is a really big project.
Also not clear if its completely open-source, they have a lot of binary DLL’s committed into GitHub, though I’m not familiar with how C# projects typically operate.
see: https://github.com/DynamoDS/Dynamo/tree/master/extern, although IronPython for eg, only has DLL’s and is definitely OpenSource. so its all a bit fuzzy where libraries come from, committing compiled code to source control is generally bad practice - and not allowed in Blender’s repo.
Not sure you mean by geometry engine? seems like it has its own libraries to do geometry, but I didnt look too deeply into it.