OLD: The parameter-number offset, between the #set and its leading #if part, is intentionally.
Effectively preventing setting the property on the last given GM-parameter (is object name ... makes no real sense for this property).
NEW: Menu-system seems to have changed (or potential is usage) in such a way that not including the last item makes no sense any more.
Not having the last item is also troublesome when checking the GM used data for potential outdated and/or misfit entries.
ISSUE: rethink if there is an other way to also store the last item(final-menu-items), including it with the others(sub-menu-items) bloats the "Unique data list" in such a way that it effectively becomes unusable. (storing last item is going to be reset in a day or two)
LATER1a: (on hold) Check if target property-name can be safely given as named-parameter here (probably. make sure).
LATER1b: (on hold) see about ditching separate legacy case of this template.