The good part is that HH will let you go minus while waiting for the exchange. They know how slow the airlines are...

When I exchanged 20K back in Oct for a PTS5 award, CO told me it would take 60-90 days for the transfer to be complete.

I called them around 85 days and they said it would be done in the next 2 weeks. It was, but that's over 3 months to complete.

CO admits they are very slow with transfers; conversely I t'ferred 10K from TW for the same award and it was completed in 11 days!