This is exciting!
One thing I think it would be important to figure out (at least in the abstract) before these become official is how these interact with async properties, and specifically with the current issues we have around isolation in the context of async properties (like @hborla discussed in this thread for functions).
Can either of these be async?
Can we take the opportunity to improve the design so if we do have an async read on a non-Sendable type you can actually use it from an actor-isolated context? For example, since these are new accessors, can we make them inherit the actor's isolation context by default (as opposed to having nil isolation?)