(1) Image sequences are not visible when scrubbing the timeline in Octane Blender. They work fine when rendering the animation, but you can not see them in preview mode.
Stand Alone does allow you to scrub the timeline and preview any image sequences assigned to textures.
Of course, there is the offset value and moving that does show the image sequence in the preview. Unfortunately, that does not help if the material uses multiple animated textures (for instance, a material with bump, normal, roughness, metallic maps that must be animated in unison). The offset slider has no input pin, so it is not currently possible to attach a value node to hook into multiple textures at once and move their offsets together.
(2) Image sequences in Octane Blender exported to ORBX do not show up in Stand Alone. Nor is there a timeline in the exported ORBX. Additionally, it is not possible to manually modify the nodes once in SA since the "Add Files" button is grayed out. One needs to use a complete new image texture node and re-import all files.