Last month there were several threads about how frustrating it was to redeem on KE using DL miles. In the one I've linked here: KE award flights using DL miles, one poster said DL seems to block all flights during KE blackout dates, regardless of origin or destination. The KE blackout date chart has specific dates for specific directions of travel, but the DL agents seemed unable to help. Others have recommended trying other partners, such as CZ (China Southern).

I'd be interested in how your experience plays out. Back when I was trying to get an SQ F award, it took 4 calls to get the right dates, and a knowledgeable agent to book it for me. Good luck!