I'm working on an IoT Industrial use case for which I need an "open" response window to communicate with the Alexa service. The duration would need to be at least 90 minutes to enable conversational interaction and drive an ambient experience for users. For a successful proof-of-concept, a user needs to remain focused on the task at hand, while Alexa responds to voice cues in the background to automagically drive IoT devices. The 8-second user response limit is unusable in this scenario. Is there a viable workaround? Or perhaps a developer program for proof-of-concept explorations to prove out new use cases?