You can still use Magick.NET in a multithreaded environment. The only difference is that you won't be able to use OpenMP that allows mulithreaded operations on a single image. If you are using Magick.NET in a multithreaded environment (e.g. WebServer) I would advise you to not enable OpenMP because I don' think it would benefit you.
If you still want make the changes then you need to rebuild the .lib files with OpenMP enabled and make sure you install the correct version of the C++ redistributable. And then you need to add the old code that allowed you to set the thread limit.
p.s. The libs are on DropBox because they change a lot and it would make the git repository big because they are binaries.
If you still want make the changes then you need to rebuild the .lib files with OpenMP enabled and make sure you install the correct version of the C++ redistributable. And then you need to add the old code that allowed you to set the thread limit.
p.s. The libs are on DropBox because they change a lot and it would make the git repository big because they are binaries.