Those have always been my thoughts, Andy.
Always thought the most sure fire bet for the connection is to go through Mother of All Battles Choke to DADES Choke in Daren. Would mean lugging an awful lot of scaf down there, of course!! The passages leading to the chokes are so similar, that they must be either end of the same choke. MOAB was partially passed on the right hand side, to Rio Dreamo, which heads off South, towards Suicide Choke at the end of Up-Dweeb in Daren, which is still the closest point between the two caves, as far as I know, maybe about 15m. But the digging there was very hard work. I wondered about continuing to follow the right hand wall of MOAB, beyond the start of Rio Dreamo. I think the wall swings more to the left and lines up fairly well with the left hand wall of DADES Choke, if the surveys are lined up reasonably after the radio locations that were done in the 90s. I recall that Stuart said that the radio location showed that the chokes, and therefore the passages leading to them, were at roughly the same level. At DADES, I think all the digging done in the 90s was on the right hand side, with the dig heading North, into the blank space between the two diverging passages. Don't know if any other digging has been done there since but I seem to remember that on the left side of the choke, there was an open triangular space, created by a long slab of rock peeling away from the base of the wall and making a bit of an undercut. It was too small to get into but you could see maybe 3m along it to what looked like a slightly larger space, with a rising sandy floor. That's my two penneth anyway!