Nonrequired parapet atop 1 hour wall - does parapet need to be rated?

[Yikes]

Type V-1 hour apartment building, 2021 IBC / 2022 CBC
Exterior walls 13' from property line.
Roof trusses have 1 hour rated roof-ceiling assembly throughout. It qualifies for IBC 705.11 exception#4 which says parapets need not be provided.
Parapets are not being used to provide a fire separation - - they exist to help direct rainwater towards the drains.

QUESTION: when non-required parapets are provided anyway(usually for drainage or for hiding rooftop equipment), do the parapets need to be 1 hour rated, simply because they are in line with the exterior walls of the building below? Do you consider the parapet part of an "exterior wall" if it's not really enclosing space above the roof level?

Proposed nonrated parapet construction, from outside face of wall:

• 7/8" stucco
• 1/2" plywood sheathing
• 2x4 studs
• 1/2" plywood sheathing
• TPO roofing, rolled up onto plywood sheathing

 

[RLGA]

I don't see why not. I guess it depends on how the parapets are designed. Are the parapets framed separately on top of the roof deck, or are they continuations of the wall framing below?

 

[Yikes]

I don't see why not. I guess it depends on how the parapets are designed. Are the parapets framed separately on top of the roof deck, or are they continuations of the wall framing below?

Where the trusses are parallel to the exterior wall, the parapets on that wall are platform framed on top of the roof deck.

Where the trusses are perpendicular to the wall, the truss manufacturer has provided a vertical member to form the parapet framing (see yellow area in image below). There will be blocking at the roof level so that the parapet framing bays are separated from the truss attic bays.