[gadders]

The TL may be right - better to deliver the right product late rather than something broken on time.

However - I would document everything.

"TL - just make a our note of our conversation earlier. You want us to pause API approach A, whilst you decide on a new design. We flagged that this would put Milestone X at risk, but you decided that it was worth the delay to improve the design. In the meantime, you want us to work on Module Z."