Val Akhmedov

Hi @OliverJAsh! I think it was added after I submitted this [issue](https://github.com/gcanti/fp-ts/issues/1484)

Here is a code snippet explaining the issue. This wouldn't compile prior to 2.11 ```ts interface Registered { type: 'Registered'; username: string; } interface Unregistered { type: 'Unregistered'; } type...

@MoAsmar for your last case, you need to check privateRoute example. As I understand @jthoms1 means different thing by route guard.

 Tried to debug this issue and found that function that creates Provider is copied in bundle 2 times, hence we have two copies of listeners and states in runtime,...

Got it work by create fork with module: /collection in package.json, getting build warn though. Now injection seems to be working fine

It would be great to have the same behavior as optionals in proto3, i.e. { scalarOptional: number | undefined }