First, thx robin1982 for letting me know about the feel. Much appreciated!
I asked my question originally because how a string is constructed is one of the biggest indicators for me of feel and stress on my arm. By your definition thus far, Prince Lightning XX (Composition: Solid core w/ multifilament wrap) is a multi. To me, it's a solid core syn and plays as such. Nevertheless, there are strings that defy their construction when played in feel/softness like AG2000 as I mentioned. Then there are strings listed by sellers as multis like NXT Duramax, NXT OS, and Tecnifibre MF that have a solid core. I haven't tried any of these, but I've played Prince Premiere Control (black) and while it's listed as a multi and would technically agree, it plays far closer to a solid core IMO.
So to me, in order to decide on strings, defining a multi as a string that has a multifilament core works best. Just saying MF is a multi isn't enough for me, but I understand why TW and you would categorize some solid core strings with multi wraps as multis. I needed more info given it's solid core, and it seems very large majority agree with you both in reports and reviews. I found only one review that says he/she can tell it's a solid core. All in all though, I'm definitely more interested in how it plays than the category it should be placed.