If you want to perform a horizontal pan "offset" effect on equirectangular footage in Resolve's Edit or Color page, a very fast to render built-in tool for the job is to use the native ResolveFX based "Transform" OpenFX feature.
When applying this effect to 360VR content, make sure to set the Transform effect's "Advanced Options > Edge Behaviour" setting to "Wrap-Around" to manage wrapping the footage around at the left/right frame border. The "Position X" slider control allows you to perform a horizontal scrolling effect to pan the footage, which allows you to change the initial front viewing angle for a video clip.
If the Transform effect is applied to footage directly in the Edit page environment, the playback speed is very close to real-time.
Special thanks goes out to Joergen Geerds for asking a workflow question that led to this post.🙏
Regards,
Andrew Hazelden
Kartaverse Developer