Thanks all. I booked the JFK-TLV in BE. Then, I noticed that there was one seat from USA-JFK outbound available in F, so I called and had it added. At the same time, they added the 2nd seat outbound in Y+ and the return JFK-USA for both of us in Y+ for the same miles. (Seems like a no-brainer, but didn't realize you could mix C and Y at the going C rate since it didn't show on DL.dumb)

I'll keep my eye on F seats opening up and switch to them if/when that happens.