Week 82: PLSS Single and Double Proportion (For the FS/PS or CST Exams)

I missed the last zoom presentation for week 82 on single and double proportion. I don’t follow the question that Danny Rodik asked at 1:15:24 in the video. As I understand it his question pertained to establishing SW1/16 corner of a typical section. There was some talk about whether the corner should be set by single or double proportionate measurement. That is where I am confused. The SW1/16 is set at the intersection of the west and south 1/16 lines in a similar manner to how the C1/4 is established and not by single or double proportion. Did I not understand the question.