I was about to post something along these lines for Serio, so thanks, that is great that you gave it a try and figured that out yourself!
Just tried it out of curiosity.
It is indeed working quite well.
Made a new menu as described here
Activated wiki parsing for this menu.
Made a Major menu Option, in your case PRODUCTS with no link.
Then an intended menu option without link where i didnt put in Text as usual but the Plugininclude as described above (replace foo with a Tiki site where the required links for the Mega Menu are in).
This is really working. Lets find useful applications for it.