Hi! I agree with you, the syntax I gave is not quite right. I've been very careful not to use any syntax sofar actually, to limit the bikeshedding. That was something I copied from another user to demonstrate. However, I agree that your alternatives make more sense.
MSG is a reference to a str, so I'd say the reference becomes an actual item in the slice here and the str itself is local here. But I don't think that matters a lot in the end, as long as you can iterate over them all. In the end, the static gets some address, and we can use that address and that address also exists in the distributed slice. If you really want to, global_register could return an address, so it's really only stored in the slice. But imo an address is still better than an index (since indices are hard when considering any linked-like model).
Finally, those are my thoughts as well, that the most flexible and functional is a static slice, possibly linked to other static slices of other dylibs when necessary