Subtitle production is becoming an increasingly creative accessibility service. New player technology allows for placing subtitles in any area of the screen and the ability to customise the typography (such as: font size, colour). Subtitles in immersive environments (XR) have taken stock from 2D creative subtitles, but require new viewing modes in order to be appropriate within the 360-degree context. Testing subtitles in XR has pushed existing modalities to make them fit user needs and requirements for enjoying the audio-visual content in 360-degree displays, however with the development of different VR content genres, and personal preferences different captions modalities need have arisen. Previous research has also identified that unless a user can experience new ideas, they generally revert to asking for what already exists. We therefore present a new prototyping framework that allows for fast visualisation and testing of new modalities as a way forward for creating and comparing subtitles modes in real life. The final aim is to rapidly prototype and identify new ways to display immersive captions in order to identify an optimal viewing experience.