As with all master classes, there will be intentional distractions present in each room, which may or may not be visible to the handler. The hides can be birch, anise, clove, or cypress and many be inaccessible or as much as 5 feet high. 5 feet is definitely inaccessible by height for many dogs, especially 14 inch tall PBGVs. No 30 second warning is given by the timer, but handlers are permitted to self time at master level. I usually set my watch to give me a 15 second warning.
The video below is Alice doing a Master Interior search at a recent trial. I VoiceOver the video to explain my thoughts as a handler as we search the spaces. The trial was at a camp, so the search areas were a craft room, a hallway, and a bunk room. This was Alice’s first time competing at master level.

Great video. Doing MI this weekend with Glee.
Totally helpful ! Hope I will read my dog that well some day🙏🏼