Your question is Design Pushback From Engineering. Take a moment with it on the right.
Talk me through your thinking if you like. When you're confident, submit your answer and I'll grade it like a real screen (7/10 or better passes).
Tell me about a time a lead engineer told you your proposed design was too technically difficult to implement. How did you respond, how did you work through the tradeoffs, and what was the outcome for the user and the team?