Dear friends. I am trying to get a good deal for a return flight in J to Singapore and I'm based out of DXB. As a newbie to Skywards and having newly moved to Dubai, I am not very experienced. However, I've read you can get much better deals through CAI which I now see to be true:

• DXB-SIN-DXB in J Flex 4,027 USD [+12,250 miles]
• CAI-DXB-SIN-DXB-CAI in J Flex 2,025 USD [+16,628 miles] + DXB-CAI-DXB in Y Flex 427 USD [+2,100 miles] = 2,452 USD [+18,728 miles]

Pay ~1,500 USD less for 50% more miles. Having never really gone out of my way for such flight deals, I had a curious thought: what if I just fly to CAI to start the above journey, but miss the last leg of the return flight (DXB-CAI) on purpose so I don't have to do CAI-DXB in the end again? What are the penalties on miles? If I try to cancel this leg while I'm already in Singapore, what happens? The SIN-DXB flight is obviously much more expensive - would I have to pay the difference? Seems so strange that I would have to pay extra to cancel a flight rather than just the lose the money I had spent already.