Should Units of Measure be capitalized inside a title?

There is a similar question regarding capitalizing units of measure, but mine is for titles, specifically. For general applications (ie; not inside titles), the consensus seemed to be no for most units (although there were a few special cases mentioned). I am wondering whether this changes for titles. And if so, how it changes. Should you capitalize the first letter? The entire thing?

My specific example is for pounds per square inch (psi). "Tire psi Below Minimum" vs. "Tire PSI Below Minimum" vs. "Tire Psi Below Minimum".

Edit: The commentator below raises a good point. But what if it's "Tire Below 72 PSI Requirement"? I don't see a way to get around using a unit there.

More info: These titles are used as alert titles to display to a user in an application.

(Part of) the answer is actually in the related topic. From the accepted answer:

Unit names are normally printed in roman (upright) type, and they are treated like ordinary nouns. In English, the names of units start with a lower-case letter (even when the symbol for the unit begins with a capital letter), except at the beginning of a sentence or in capitalized material such as a title.

Note that this is about writing the units fully! So pounds per square inch could be "Pounds per Square Inch" in a title.

For the abbreviated forms the standard rule is that the abbreviated form is capitalized is the unit is named after a person. I believe neither the pound nor the inch were named after people (sorry Ezra), so it would be psi. (Strictly speaking, ppsi, p/si or pi^-2 would be even better, but they are not SI anyway). There are some other units and derivations that are capitalized for other reasons, by the way (B = byte, b = bit; m = milli, M = mega).

Capitalizing abbreviated units that are normally not capitalized is generally a bad idea, because there are too many cases where you actually change the unit. The unit p could be read as the P for the quantity pressure, for instance, instead if the unit pound. So if you use psi, I would not capitalize it, even in a title.