Unary minus precedence preference

[KeithB]

"I’m just going to throw this out there. What if instead of using the standard/de-facto dash for both minus & unary minus, using a superscripted dash or even overline (opposite of underline) or maybe even underline for a number intended as a negative number? "

You mean like the Prime?

(unary minus)2^2 is still -4.