Can I change flights in Singapore, KL, Bangkok, HK, or VAE when flying to Phuket under Sandbox immigration rules?

A traveler in Germany wants to know about allowed routes to Phuket and the possibility of changing flights during the Sandbox immigration process. Based on the comments, it is possible to change flights in multiple places like Singapore and Kuala Lumpur as long as everything is on one ticket, and luggage is checked through to Phuket. However, transit through Bangkok is not allowed at this time.