PivotProof vs Lean Canvas: the canvas organises. The tank decides.
A canvas gives an idea a shape. It cannot challenge the assumptions you put in every box.
Use Lean Canvas when
You are early enough that you have not yet stated the customer, problem, channels, and economics clearly.
Use PivotProof when
The canvas looks convincing and you need an adversarial read before treating it as evidence.
The verdict
Do both. Use the canvas for the words, then use the tank to identify which words are load-bearing lies.