Hi Martin – thanks for the response. I ran your plugin on a copy of my site on a separate test account, so no damage was done to my production site.
Let me clarify a few things. The More Tag I am referring to is in posts where the “Read More” was inserted into the post manually by the author. It appears in the post as the literal text: “<!–more–>” (without the quotes).
As I am changing themes (hence the use of your plugin), I no longer need manually inserted “Read More”‘s, so I have developed a workaround. Before running your plugin I will use the plugin “Better Search Replace” to replace the “<!–more–>” with a blank value. I except then your plugin will work for me.
I wanted to let you know as the issue does not seem to relate to images. It seems everything after the “<!–more–>” is lost, even if it is only text and there are no images.