I understand it is not required... by convention. The wording itself is neither explicit nor concise enough to say what way it should or shouldn't be done.
...and it wasn't the last sentence of 110.14(C) "general statement" that I am referencing... (see highlighted quote of text below).
General statement does say you cannot exceed the lowest rated temperature.
Subparagraph (1) says to base ampacities on Table 310.16. Is not ambient temperature correction a part of Table 310.16? (a)(2) and (b)(2) do use the word "ampacity" and per Table 310.16 ambient correction is required for conductor ampacity.
However, one must apply adjustments appropriately. Take for example Norb's situation where most of the run is on the roof but both ends of the run(s) drop down into and are terminated in a 30?C living area. Conventional application of using a higher temperature-rated conductor for termination adjustment would be appropriate.
Yet again, let's say we have a similar scenario but the load end(s) terminate on the roof into 75?C-rated mechanical lugs and the supplied devices, equipment, and such has an equivalent or better temperature rating. The first sentence of 110.14(C) says we must select and coordinate the ampacity so as not to exceed the lowest temperature rating of any connected termination, conductor, or device... which is 75?C in this case. So do we not have to correct for ambient temperature the tabled 75?C ampacity to determine the current level at which the conductor exceeds 75?C?
What if there are more than 3 ccc's in the run? Again the key here is by the first sentence of 110.14(C), we have to determine at what current level does the size used exceed the permitted temperature.
I have no clue at all what your trying to say here.
I know you think it's clear but for me it's like trying to find Waldo.
IMO this is what matters
Conductors with temperature ratings higher than specified
for terminations shall be permitted to be used for ampacity
adjustment, correction, or both.