Hi Sanju,
The input on ABNA transaction is only used for the "online" created GL document.
For areas that do not have posting set to "Realtime", the GL posting is done in a separate step and the input from the ABNA screen is no longer available (Even with "direct" posting setting, then it feels like the posting is done simultaneously but in reality it's a separate process and it starts after ABNA execution). So even in case your User could enter these fields in ABNA, it would not have any effect on the created GL document.
So check your area settings. If affected depreciation areas do not post "Realtime" then you should tell your User that it makes no sense to enable these fields when posting only to such areas. Because even when the fields were there, they would not work as expected.
Best regards, Michael