Given the uncertainties of the hand, a 2D rebid, which
makes a plus score very likely, might be a reasonable action at
match points if trying to protect a really good round. Still, it is
a huge underbid.
The hand, however awkward, adds up to 18.00 KNR, and
at IMP scoring I need to show the full values. I would
rebid 2C, and continue with 2NT over 2H. I take this to have
the same meaning as in B-13: non-forcing, spade stop, better
than minimum values for a light reverse, no heart fit.
I'd expect responder to continue to game with 7,8+ HCP and a
diamond fit or 9,10+ HCP in a misfit. I'm not sure what a
responder whose only values are d-AJx is going to do, but
we will bid more of the games we should bid than we would
with weaker sequences.
Fred.