You can do some weird stuff to GC in C#. I haven't looked at it in several years, but I'm pretty sure there's a way to suspend GC at runtime. There's definitely a mechanism to force immediate GC, and functions to exempt an object from GC.

C# is a lot more flexible than people give it credit for, I've seen some absolutely amazing things built this way. Of course, manipulating C# in unexpected ways is an absolute nightmare, but with enough determination you can do about anything