I got a response from Handango about the upgrade. I had just recently purchased 1.5 just 4 days ago. They agreed to refund me my original purchase after I purchase the full copy of 1.6. Sounds good to me.

My only issue is my original purchase was using the LAUNCH20 20% discount code and that won't work now. I don't want to buy the new one at $39.99 and only get $31.99 refunded. I am awaiting their response.