Attachment 104333
If you plot it out in a graph it will make more sense. Where the min and max overlap is the boundaries in which a shift will be allowed to occur, provided!!!, post shift acceleration is met and the governor pressure has reached the point to flow through the circuit. HP Tuners is using psi in the post shift acceleration table which I don't believe to be correct. There is a lot of similarities here between the 46RE and 48RE and in the 48RE it is NOT psi, it is a calculated acceleration value, NOT psi. The post shift acceleration table is minimum calculated post shift acceleration required to allow a shift. Your boost pressure is governor pressure to force a shift and your hold pressure is governor pressure to prevent a shift.
It will take a manipulation of all of this to adjust your shift points, moving your min/max tables (both throttle and OSS rpm) to where you want, raising or lowering governor pressure, raising or lower boost and hold pressures and raising or lowering the post shift acceleration tables.