Bookshelves atop SVS subs? Nautilus 805 DIY 801

I've wondered if anyone has tried placing bookshelves atop a pair of subs, envisioning a sort of DIY 801's.

Since I have Nautilus 805N's already, I'm part way there.

It would seem similar to the 801's but steerable, so more like KEF 105's or 107's.. or Wilson WATTs with Puppies.

Then I guess the next thought is, do you really need 2 subs vs just getting one incredible sub with the bookshelves and call it good.
You mean like my Ref 3A Supremas w the Royal Master monitors atop a pair of passive isobarik subs? Or the Von Schweikert 4, 4Sr and 4 jr, or the Hyperion (forget which one)? Lots of speakers set up that way these days. One concern is to prevent the vibrations and/or potential cabinet resonance from the subs from affecting imaging etc in the monitor/bookshelf. As to second question, 25 years ago lots of folks paired the Spica 50s w a Kinergetics or other really high end sub. Nowadays, they call it a 2.1 system. Some folks like -em, some don't. Whatever floats yer boat....