To provide enhanced operation of data storage devices and systems, various systems, apparatuses, methods, and software are provided herein. In a first example, a data storage device accumulates write data into a cache storage region prior to committing into an archive storage region and maintains a data structure that tracks the write data in the cache storage region. Responsive to receiving first write data into the cache storage region, the data storage device establishes first tracking elements in the data structure for the first write data in the cache storage region. Responsive to receiving second write data directed to storage locations overlapping the first write data, the data storage device accepts the second write data into the cache storage region and establishes second tracking elements in the data structure for the second write data in the cache storage region without modifying the first tracking elements.