Originally Posted by craigthemif

Bags will be through-checked.

You will arrive into T4S and clear passport control before going on an underground train to T4. You will be required to go through transfer security there and you will be free to head to the Dali lounge on a J ticket. It should all be quite straightforward.

4 hours isn't enough time to do anything outside of the airport. So your choices are airport shopping and the lounge...