No-one is suggesting preventing editing - if you change your mind about what you have posted edit the post (to a minimum 15 characters

) -- obviously editing a post in a locked thread is not possible.
Other BB software prevents the deletion of a post once someone has posted after, but allows editing of prior posts. It works well, and if it is
really necessary the mods can delete/move/rename the thread anyway.
I also doubt PPRuNe need approval from its users to make such a change if it/they deem it worthwhile -- as we have been told previously, it ain't a democracy
BTW, PPRuNe Radar, aware of the Lydd Thread hence my referring to it as a near-miss (thread-prox) rather than a deletion - good pilotage prevented it becoming a statistic