Accounting Flexfield Change ?

 Hi All,          We have requirement to change the values for last two segments of the Accounting flexfield. Currently we have the below accounting combination.

       001.415.76854.01.01 (value for last two segments are 01 to 04 with different combinations)

       ------------------.01.02

       ------------------.02.03

       ------------------.04.01

     Now the business want to use different values for the last two segments (11 to 15 with different combinations) as shown below.

     001.415.76854.11.12

     ------------------.13.11

     ------------------.14.13

    -------------------.15.11

                        So,If we want to use the new combination,we need to make changes to the combination in all the places where it is used (like AR,AP,GL set up).Did any one make this kind of changes ?Can we make these changes without any issues ? (The business is aware that they will have issues in viewing the existing transaction data,and they are okay with it).Please reply with your opinions and answers.