Thought before Started Blogging 2: Knee and Feet Alignment

To make sure one's posture is strong, the upperbody must be supported well by the legs. Thus, the legs must in the correct alignment to support the body. The knee must be supported by the feet. If the upper body's weight pushes against the knee, and the both knees are too wide open, the strength from the feet is not transferred to the knees. The knees then easily collapses upon pressure. Imagine the letter A. The feet and knee must have such an arangement. So lets say a force is pressed on the apex of the A, the letter is stable due to its structure and won't collapse. That is the idea between the knee and feet alignment.
At the same time, the knees must not go past the toes, or else it would be bad for the knee and one can get pulled over easily. With the A line sturcture of the knees coupled with the knees not exceeding the toes, one can have a stable and strong lower body structure.

However one query that i have is that, if they say that the knee does not go past the toes, do they mean this:

Where the blue line is the line of sight by which to judge if the knee exceeds the feet.
This is because many of the pictures of the masters that i see practise with their knees like this, meaning 90 degrees. And personally i feel this is the correct way.

Or should this be the correct way? Where the knees do not exceed the perpendicular line drawn from the ground starting at the tip of the feet.