The OP wanted something to be 14.7 mm, this told me it was a new user most likely making something for 3d printing and at a very small size. So I said it’s not advisable to use mm, I should have worded it more correctly and said not advisable to work in mm when making something for 3d printing. I did say it but not perfectly joined up with the correct punctuation. But I through it in to help the op avoid the issue before it came up.
If you look at the Dave Method thread I linked you’ll see how the tiny face issue can be avoided.
I said work in Meters and export as mm. .stl files are unitless so it doesn’t actually matter what unit you use, just what unit you tell it to be.
So you coming in saying, it doesn’t matter , use mm, it works for me. Was incorrect information in the context of what we were talking about. I’m comfortable with and use all measurements, imperial and metric depending on the situation.