Salary Sacrifice - Different amounts

We have a number of  employees who salary sacrifice pre tax either an agreed $ amount for benefits or additional superannuation. For the pre tax benefits amount the only way to set up a new employee's request is to create a new payroll category otherwise it "takes" the last figure which was set up. The same for Super. An example - super

Using Salary Sacrifice Superannuation/ Standard Pay/ Calculation Basis equals $00000 dollars per Period

Employee 1 - set up with $600 entered

Employee 2 - set up with $750 entered 

Employee 3 - set up with $2000 entered

all are now defaulting to $2000 and luckily I picked it up before finalising the payroll

Benefits - Salary sacrifice pre tax

My predecessor has create ed a separate payroll categories for each employee's salary sacrifice, eg Salary Packaging Ded - Emp #1, #2 ## etc...for all 14 employees currently using the system and the 35 ex employees who used it

Calculation basis - equals different rate....per pay period

Is there a better way of doing both of these as I don't want to incorrectly "over" sacrifice someone's superannuation and have to remember to change the benefits category name to ZZ....Ex Employee every time someone leaves