That feels very bad to me. If a retentionist country wants to hang people, it shouldn't add endless insecurity on top of the punishment.
Edit.: interesting that this is controversial enough to be downvoted. Remember Trump signing the death warrants of 13 federal death row inmates during the last 6 months of his presidency? Yeah, once you are legally condemned to death, your actual execution is a matter of electoral random walk, which is pretty nasty.