Hi @dmforbes ,
I asked the PTC R&D in PTC internal blog and received a feedback:
"This is not current functionality for Vuforia Expert Capture."
and further comment of the developer:
"The issue is simple: Studio experiences allow the author to do their own JavaScript and provide lots of hooks for them to monkey with the behavior.
Expert Capture procedure playback provide no hooks to modify any behavior. They procedures are played in a standard one-size-fits-all fashion."
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Means this is not possible with the current functionality
And also as workaround you can use a Vuforia Studio experience with one video widget where you can use a QR code to call the experience and then use a Image Target (pointing to the same QR code / not so good but mostly works/ in this case you have as Image Target a picure of the QR code/. So when the experience will load you will start the video widget by javascript