Memoso and Vorians: This can be fixed more easily by activating "Landscape Fixes for Grass Mods.esp" during the merge and placing that plugin after the plugins that are being merged. That is, put it after "Verdant - A Skyrim Grass Plugin SSE Version.esp" in the MO2 Plugins window, but don't include it in the zMerge load order. I don't understand how this renumbers the records of the other plugins, but it does for me.