I'd discard the

, on a 1,4, or 6 since it puts us in a pinfu tenpai.
Granted, one of those waits is dora, so it may make it hard to win on
that tile, but if we draw one dora, it won't mess up our hand.
However, I'd still tsumo this hand on a

or a

.
I would probably only go for endless if a dangerous middle tile forced
those 9-dots out.