I would love to embed Dyalog but last time I tried I wasn't smart enough. If anyone from Dyalog feels like throwing cycles at it let me know!
They have a .NET Interface document: https://docs.dyalog.com/latest/dotNET%20Interface%20Guide.pd...
And more general documentation: https://www.dyalog.com/documentation_190.htm including one for classic Windows .NET (instead of .NET Core) and one "APL As A Shared Library" which is about integrating with other systems using C (making a C .DLL) instead of .NET.
Thank you, jodrellblank, for being patient with me and for this information.
[1] https://github.com/briangu/klongpy
[2] https://analyzethedatanotthedrivel.org/2018/03/31/NumPy-anot...