When someone is skilled in one area, they can fall for the idea they are skilled in all areas. The big advantage of co-founders are honest peer conversations o

When someone is skilled in one area, they can fall for the idea they are skilled in all areas. The big advantage of co-founders are honest peer conversations of what worked, and what failed. Ultimately to be a good founder requires that they are able to post-mortem well, and identify weaknesses. Personally I would let the person know i had advice, but then keep the advice to myself until asked. Ultimately all decisions are compromises, and unsolicited advice on why a decision is "bad" without all the facts is seldom appreciated. My first goal would be to find out the constraints that lead to the decision in the first place.