What controls which scratch tape is mounted next?
Release: TLMS..00200-14.0-TLMS-TAPE MANAGEMENT
CA 1/TLMS do not control the order in which scratch tapes are mounted. The software provided by the vendor of your ATL/VTS device will determine which tape of the available scratch tapes should be mounted. Most VTS devices have an option to hold on to a scratch tape for a given amount of time before it can be reused.