Use Black Magic Design's Fusion Studio (Resolve?) with Reactor to directly make an intermediate movie in any reasonable length. Here double the length of the bash version. Reactor is not restricted to yaw from -180 to 180 as v360, but it works here too.

fusion_RotateEquirectangular.png
Loader (Equirectangular), set timeline to: "0-719"
Resize1: "3840x1920"
RotateEquirectangular:
Set keyframes "Y Rotation = -180, time 0", "Y Rotation = 180, time 719"
Saver1: "Quicktime movies, Apple ProRes 422"

Yrot2.png

rotateEqui-keyframes.png
Install RotateEquirectangular from:
Fusion Reactor - All - Legacy - Tools - VR
"KartaVR Tools | Legacy Transform"
then it can be found in:
Reactor/Deploy/Macros/KartaVR/Transform/RotateEquirectangular.setting

legacy-transform.png