Yes, this can be achieved by selecting Layout as "Full Screen" and Display as "3D Space" under Hotspot settings (right pane of the authoring/preview screen). The video will stay active till user closes the Hotspot video by clicking on "X" mark.
Using the 3D space option will help as shown in the below screenshot.
Note: This is not supported in dual-view in the mode in WebVR mobile.
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