Correction: I just found a way to ask GPT Builder inside Create tab conversation to generate new options for icon design using DALL-E. It's almost as smooth as working in dedicated DALL-E conversation, except the conversations inside the GPT Builder reset and history is not maintained so it's still better to keep your icon design process in a separate dedicated conversation with DALL-E in ChatGPT. This allow you to go back and download your creations for tweaking in other apps.