We want to reuse Flat Fee PDBA

We are currently defining Flat Fee PDBA with a set amount of a daily fee of that the employee earns if they work a specific shift.  It originally was supposed to be 2 or 3 but has turned into about 25 - 30 and growing. 

Set up is as follow:

Pay Source: F

Shift Diff Method: 1

Amount or Rate: $XXX.00

 We are looking to reuse the DBA to when the rate is no longer used.  Does anyone know if there is any issues doing this.  In my testing I have not come across any but I have only run 3 payroll, have not done any year end processing.