Be sure to follow the code where-as any cable that has VOLTAGE POTENTIAL on it must be a FEMALE CONNECTION so that when you plug the cable into a HOT VOLTAGE SOURCE with a MALE CONNECTION then the other end of the cable won't be able to touch any thing if energized.
The TWIST LOCK FEMALE SIDE INLET keeps you from accidentally pulling the connector out of the socket when energized. All trailers I have ever seen use them on the trailer side of the shore power cable.
If your RV30A to 15A adapters are the small round plug-in type you need to get rid of those and only use DOG-BONE type Adapters that are around 18-inches long. The small puck type will get hot on you over time and melt down your cable connectors making you have to replace them...
Roy Ken