I have recently noticed an odd pattern in code that I write.
First I add a helper method to a unit test to speed up setup.
This then become so useful to manual testing that it gets added to the test tools in the UI.
Subsequently the customer service team start to ask about this feature.
The general rule is if it is going to speed up development consider adding the test tool to the customer service ui. Edge cases in code will become customer service wrinkles.