Digital Wellbeing by Design: Safeguarding End-Users' Time and Attention in UI/UX Practices

User interfaces, particularly those of social media, promote mindless usage through Attention-Capturing Damaging Patterns (ACDPs) like infinite scroll and content autoplay, prioritizing user engagement over digital wellbeing. Recent work suggests that a promising approach to realigning technology with users' digital wellbeing is to prioritize it by design. Building on this idea, this paper explores how to support designers in identifying ACDPs and surfacing wellbeing-oriented alternatives. We first defined and assessed a multi-modal prompting technique to detect ACDPs in Figma prototypes and discover alternative designs that may promote mindful and active technology use, assessing its outputs with 4 experts in deceptive designs. Then, we integrated the prompting technique into a plugin for Figma, and conducted a formative lab study with 15 UI/UX designers to explore how such a tool may support early-stage reflection on ACDPs and its perceived fit with existing practices. Results suggest that the plugin can inspire designers to reconsider their choices early in the design process.