Avoiding unnecessary allocations matters, and this is why static anonymous functions were introduced in C# 9. In C# 9 lambda or anonymous methods can have a static modifier.

Learn when static methods can’t be unit tested and how to use wrapper classes and the Moq and xUnit frameworks to unit test them when they can When building or working in .NET applications you ...

The C# method you're calling doesn't need to return a Task object even if called through invokeMethodAsync. The static C# method I've been using, for example, simply returns a string: [JSInvokable] ...