Respected Sir/Ma'am,
I understand your business requirements behind the requested changes, I myself make a point to develop in such business friendly manner, I have 3+ years of years of experience in developing on google app script, and your use case is not a very uncommon one, I assure you a quality update as per your expectations in the promised time.
Looking forward to discuss the intricate details about the project, before the development can begin.
Regards
Murtaza Sadriwala