When support is turned on with already replaced enemies, the nests on the side of ordinary enemies will stop mutating (just mutating, they will remain working). Also, the method will not work if the version was 1.0.11 and higher, because the setting is remembered so as not to replace enemies when starting with a settlement on the other side.
But, in truth, the wording "current maps will work the same as..." incorrect for the upgrade from 1.0.10 and below, since the setting will be taken from the startup settings. Thank you
But I am glad to see that you are satisfied with the result.