SINGAPORE’S HERITAGE DISTRICTS aren’t known for cheap beds. CUBE Boutique Capsule Hotel is betting that they can be. Two years after opening its first capsule hotel in Chinatown in 2016, CUBE has opened a second property in Kampong Glam, the historic Malay-Muslim quarter around the Sultan Mosque. The new hotel sits inside a handsomely restored shophouse, the narrow, multi-story row buildings that define old Singapore, and it’s built for a very specific traveler: young, digitally fluent, and more interested in the neighborhood outside than in the square footage inside.