Hello Smart,
As far as the reasonability of client's requirement is concerned, it should stop at certain limit., like present one. Secondly, often we confuse about the client requirement. Mostly what happens is that he wants to see these changed filed names in the reports like IW28. Confirm that and if it is so in this case too, then get one custom report developed for him with custom column names. It is a simplest job for ABAPer. Or you can do it yourself with a simple Infoset query (if you know), where these field names can be changed. I had such requirement in this area where I developed ZIW28 through Infoset query using tables VIQMEL, CRHD, QPCT.
Regards
KJogeswaraRao