The fact that you just multi posted in this thread making two different posts after each other by quoting different posts, pretty much means a no. It sometimes can happen that you accidentally posted the same message twice due lag. In such a case normally if a mod would check it, there shouldn't be any repercussions because that has happened on more than one occasion to the mods themselves.
However this does not apply to your case, for some reason you don't use the edit or multi-quote button. Both buttons pretty much invalidate the necessity of a merge button as their purpose is to avoid multi-posting. It pretty much comes down to that you want us to install a button because you don't use the existing ones fully. If you don't use the buttons that avoid multi-posting, why would you use the one that would solve it? Apparently you already received an infraction once for multi-posting, still you did it again in this thread, which makes me think you wouldn't use such a button either way. Not to mention that you find it annoying to delete a post is not a reason for us to install one that merges them.