As many alluded to, practice can be used for many purposes.
1. Is to understand how all the balls in your arsenal relate to each other.
2. Is to affect muscle memory, i.e., practicing feel, repeating shots, spares, etc.
For #1, you need to actually use your current equipment.
For #2, I would use an older piece of equipment you are comfortable with. If it has a different feel than your current lineup, i.e., different weight, spans or pitches, it will not be of much good.
There is generally a limited useful life of any ball, especially the higher end equipment, I tend to practice very little with those. I have an old Ebonite V2 that I like to use for practice, but when I don't carry it, I will simply alternate my arsenal every handful of frames.
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