Explorative and live development environments flourish the most when they can impose restrictions. Forcing a specific program- ming language or framework, the environment can better enhance the experience of editing code with immediate feedback or direct manipulation. Lively Kernel’s user interface (UI) framework Morphic provides such a development experience when working with graphical objects in direct way giving immediate feedback during development. Our new development environment Lively4 wants to achieve a similar development experience even though targeting general HTML elements. Web Components as a new Web standard provide a very powerful abstraction mechanism. It allows us to use plain HTML as building blocks for our tools. Unfortunately, Web Components miss proper capabilities to support run-time development. To address this issue, we use object migration to provide immediate feedback when editing UI code. The approach is evaluated by discussing known problems, resulting best practices and future work.