On Wed, 12 Oct 2022 21:14:52 -0600
Gavin
As a recovering string theorist, I cannot help but speculate that this rule extends to spherical coordinates in any number of dimensions. However, if you don’t want the space, you can use 135\unit{℃}, which does not add a space.
Will 135\unit{℃} ever break between the digits 135 and the "unit"? I agree that \unit should probably use an \mbox to prevent unwanted breaks. The other role of \unit, I understand, is to uniformize the representation of numbers (digits).
Related, \unit{90°} does not seem to introduce a space, as indeed it should not.
So ℃ needs to be registered as a degree and prevent any spacing.
Also related, using \unit for just the units, and not the number, is useful when they follow something that is not a number, like a vector: $ \vec v = (4.0, -3.2, 1.5)\unit{m/s} $. You frequently do not want a space in that situation.
Why would one not want a (small) space before m/s in the above example? Alan