When A and B are disjoint, you don't need the tag unless you for some reason you require that `Maybe<Maybe<T>> != Maybe<T>` holds true and don't like the collapsing semantics of unions where `Maybe<Maybe<T>> == Maybe<T>`
In practice, the cohabitants in Option/Result types are almost always disjoint. So you spend time wrapping/unwrapping Some/Ok/Err for no value add.
Why would you want segmented stacks, cgo FFI overhead, goroutines, & asynchronous preemption for a game engine? Odin is better suited than Go is for this type of software. Almost any programming language would have been a better choice here. This is rage bait I'm sure.
We aren't discussing unions in memory layout, but in type systems. This also clearly indicates you aren't qualified for this discussion.