We used to own a 2BR at KBC - from January 1999 through fall 2014. We sold our KBC after we bought into the Marriott system.
Unless there has been a change, the eight 2BR units on floors 3 and 4 are in a different category than the eight 2BR units on floors 8 and 9. The eight units on floors 8 and 9 were the first 2BR units to be sold as timeshare. That's what we owned, and after they converted the eight units on the two lower floors, we could still only book units on floors 8/9. I'm pretty sure the floor 3/4 owners were restricted to only booking other floor 3/4 2BR units.
You need to find out which category you are buying - floor 3/4 or 8/9 - because unless they have changed something, you will be restricted to booking on those floors. Floor 8/9 units tend to sell for more than floor 3/4 units.
All of the 2BR units on floors 8/9 were sold with the same Ocean/Scenic view category, but all are corner units with at least some view of the ocean from the lanai. The lanais are wraparound, "L shaped" lanais with a short side and a long side. See the attached diagram below of floor 8. The rooms on floor 9 are identical, with the only difference being the short section of lanai on the end of each unit. That section of the lanai is bigger on floor 8 than floor 9, so we always requested floor 8.
Unit 839 - the long side of the lanai overlooks the pool and ocean, looking toward the island of Lanai. The shorter side looks south toward the Honoa Kai condos, the ocean, Lanai, and the Kaanapali resort. We stayed in this unit once, and it was our favorite.
Unit 834 - the long side of the lanai overlooks the Star Market grocery with the West Maui mountains as a backdrop. The shorter side looks south toward the Honoa Kai condos, the ocean, Lanai, and the Kaanapali resort (in a similar view to the end section of unit 839). We stayed in this unit the most.
Unit 824 - the long side of the lanai overlooks the miniature golf area (if that is still there) and the ocean, looking more toward the island of Molokai. The shorter side looks north toward Kahana, the ocean, and Molokai. We stayed in this unit once.
Unit 829 - the long side of the lanai looks toward the West Maui mountains and north toward Kapalua. The shorter side looks north toward Kahana and Kapalua with a view of the ocean and Molokai. We never stayed in this unit, so my view description is based on what I think it would be. Not sure if you can see the grocery store from it.
Units 939, 934, 924, and 929 should have identical view descriptions as their corresponding units on floor 8. The units on 3/4 are in the same basic locations on the corners of the back section of the tower, but they are obviously lower with less expansive views.