Reviving this thread because this pops up as one of the first results on Google:
There is a plugin called UnrealSharp that you can use to write C# code in Unreal using .NET 9 (not Mono).
I wanna add that for some people being able to use a specific language is very important, for two main reasons:
- they already have extensive knowledge and experience with that language
- they want to use shared code, for example in the making of an online multiplayer game, they might wanna write the server application in C# or whatever language, and then share some of the data classes with the Unreal project, without having to rewrite them in C++ and maintain two versions of each shared class
If there’s the ability to use it, then why not, unless there’s some major drawback like performance.