It's not permitted to edit a self-deleted question. To do so, one must first undelete it. Following a number of Collatz-related questions I lost my question asking rights the moment I undeleted my self-deleted question in order to copy the post content, before deleting it again myself.
Whether this was an automatic algorithm or involved human intervention, I don't really care. Anyhow, I'm happy to accept my loss of rights was justified given site policy and my relatively low competency.
Notwithstanding that, I was wondering if there might be any appetite or interest in this further Collatz-related question with which the community might be able to help me? My understanding is that questions pertaining to some aspect of an open problem are not off-topic.