12 megabytes doesn't sound too bad for the things you mentioned, especially if it's a constant cost.
> The application IL code is perhaps 50 bytes to for hello world.
A Hello World assembly in .Net Core 2.0 is 4.5 kB.
Out of that, the IL is 11 bytes, though that doesn't even include the "Hello world!" string.
The number might shrink as the linker gets more aggressive but i wouldn't count on it much.
The application IL code is perhaps 50 bytes to for hello world.