Currently you have to enter constant repetition numbers for your field layout objects (Inspector Tab Data). I like to use a calculation for those numbers.
Repeating fields are sometime great to create better layouts enhancing the user experience. With a flexible starting repetion number you can create even better layouts. For example, you could create a paging effect for the repeating field.
I understand, it might create layout design problems if the total number visible repetitions would change. But that could easily be solved by keeping the number visible repetitions fixed. Instead of entering start and end repetition number, you could enter start and "length". Make the start value flexible and the length value fix.