Has there been any development with being possible to allow notifications on both Apple Watch and iPhone at the same time. This is an urgent need and possibly considered as a design fault not being able to choose in the options feature?
iPhone 11 Pro Max
No, currently that is not a feature, and Apple will not share anything except what is released. See this support document about how notifications works with iPhone and Apple Watch. Notifications on your Apple Watch - Apple Support
You can provide feedback to Apple that you would like to see that feature. Use the feedback link here, Product Feedback - Apple
iPhone and Watch combined notification
