When testing content that leverages VTT captions, I found that all captions with styling align:end position:90% are hidden on this video. I believe they are out of viewport.
Unfortunately we have no any affect on what is in the VTT. So we can not re-parse it on client side.
Roku Video component have some fields which customize the caption but neither of them related to position or alignment.
https://developer.roku.com/docs/references/scenegraph/media-playback-nodes/video.md
There was one videoPlayer component in the far past which supported an ability to manipulate caption text, but that component is deprecated. https://developer.roku.com/docs/references/brightscript/events/rocaptionrendererevent.md
Is there a solution via development, or do all VTT files need to be created without alignment and position settings?