To hyphenate or not to hyphenate: Grammatically correct or aesthetically pleasing text?

Marketing is asking us (Development) to change some UI text to be grammatically incorrect. I think it's because they don't know better, but maybe they do. Specifically, they're basically asking to remove hyphens from compound adjectives (e.g., 'thirty-foot wingspan', 'late-fee messages').

That would change the meaning of the text. But maybe 95% of users don't know better either. In which case, there's an argument to be made that grammatically incorrect equates to a better user experience.

And there is one case where I myself have opted not to use hyphens even though they are called for, grammatically speaking. Example:

"Show credit card transactions"

I'm curious if anyone else has settled on a rule for this. Or if there's a style guide that has good guidance on this question.