timecodeRate attribute from ACES Container would be useful but needs clear use case

[JGoldstone]

The ACES Container File Format standard (SMPTE ST 2065-4:2023) defines a timecodeRate attribute, but does so without giving a use case:

The timecodeRate attribute shall be of type int and shall specify the nominal playback rate in frames per second, rounded to the nearest integer value. When the nominal playback rate corresponds exactly to the midpoint of two integer values, the timecode rate shall be equal to the value of the nominal playback rate rounded to the nearest higher integer.

The motivation for this attribute is unclear. Does it exist solely to have a different rounding mode than the default IEEE 754 one (where the argument to the rounding operator is the value of the framesPerSecond attribute controlling playback) and if so, why is that rounding so important as to need to attach a new temporal attribute?

Note that this attribute is not defined in SMPTE's camdkit proposal, only in the ACES container spec and software applications or libraries implementing that spec.