Thank you for your question. A #5 Halex conduit hanger works 2" EMT conduit and 2" RGD conduit.
Yes, this product is adjustable to secure both the 2 inch and 4 inch sizes.
5/8 rod is too big for this connector. Don't expect an answer from Halex as they don't seem to know what a hanger rod is. You would have to drill the hole out to accept the rod and that would severely weaken the connector