no experience with metadata menu, unfortunately…
i have no major experience in coding and obsidian inner workings as regards plugins but it could be difficult to have a listener to check the status of a checkbox
it would be easier to make a Templater Js Script and assign an icon or hotkey to it which will change the value of activated property to true in the frontmatter and create the frontmatter property key result and some value below it
but i agree it would be nicer to communicate through the checkbox…
another workaround would be the meta bind plugin and maybe hooking it up with dataview as in the method linked in this post