From an external developer: "We are using the NFC triggered onvrdisplayactivate event to switch the user to WebVR mode. But sometimes the WebVR load process fails if a user inserts the phone in the viewer, closes the lid fast enough, and the cylindrical-button on the viewer touches the address bar section of the browser and interrupts the WebVR flow. To circumvent this, we are now switching to fullscreen mode first and then to WebVR mode (which would now require iframe embeds of the player to have both of these attributes)"

It's worth checking to see if there's anything we're doing to delay the time-to-DON after requestPresent is called. If it's not something we can control, maybe we could have a brief grace period after requestPresent during which the browser chrome ignores touches. (Would need to be limited to prevent abuse.)