I'm not sure where you got the information that UPS management hates 22.3 jobs. If the jobs are the right combination and the employee works both shifts, it can be beneficial to the management team, particularly from a staffing perspective. If an employee works the night sort and then preload, chances are the shifts are covered.
As far as the jobs not being desireable, the jobs are the combination of 2 part time jobs. In most cases the hours for the 22.3 jobs are twilight, night or preload, AM and PM air driver.
Nothing is easy in the business world any longer, it is what it is at UPS.The name of the game is to keep our service levels where they need to be keep our commitments to our customers.