Shipping code is a partnership between you and your customer.
If you are late on something (for whatever reason), like any good partner you probably owe them a gimme, a goody, something extra.
That little bit of UI trickery they were looking for that they didn’t originally ask for, give it to them.
That back-end functionality that correlates their data, find the time and make it happen.
No one is saying you need to give them everything in the world to make them happy.
But you need to remember it’s a partnership, almost like a marriage, where there is give and take, and if you are always taking and they are always giving.
Well that is not a partnership and that’s not the goal.