I can’t seem to get this to work anymore, but at some point I’m sure it did. I am modeling in inches. If I set my dimension style’s Linear units to inches, I don’t have a Feet & Inches option in Linear formats. If I set my Linear units to feet, and select Feet & Inches, something that is 10.5" in model will dim out as 10’-6". I seem to remember this working correctly in the past (that with linear units set to feet, 10.5" would dim out as 0’-10½")
I also wonder if it would be prudent to add a Feet & Inches linear format under the Inches linear units, which should be the exact same as Feet & Inches under feet linear units (when they are working correctly, not as they are currently). My concern is that someone who is modeling in inches might worry about length factors being off by a factor of 12 when having to select Feet as a linear format.