You just need to set requiresOnDeviceRecognition to true for the behavior you're looking for. Note isFinal seems to be for server based results only so isFinal is never returned when you use on device recognition.
				// Keep speech recognition data on device
				if #available(iOS 13, *) {
						//recognitionRequest.requiresOnDeviceRecognition = false
		 recognitionRequest.requiresOnDeviceRecognition = true
				}
computer assistant
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Hi All, I use continuous speech recognition in an app I have for macOS by setting this bool on the request.
recognitionRequest.requiresOnDeviceRecognition = true
DisadvantagesResults are not as good as server based results
Limited device support
AdvantagesWorks without an internet connection
No recognition limits
Better privacy for the user
Reference
Cheers