you've got me questioning myself now 😂 maybe it wasn't that border after all, I should've checked my facts before replying!! Let me double check now. Either way, we didn't have to stay the night.
Not necessarily true, I've used the border crossing in Trat to Laem Khlat, didn't need to stay the night. Stamped out of Thailand, stamped in to Cambodia, there for less than 15 mins and then stamped back in to Thailand. We paid an extra 300b per person instead of staying the night.
Koh Chang is great. Lots of nice beaches, bars and restaurants. Plenty of massage shops open also. You can easily get to Koh Kood and Koh Mak from here also.