jhubert: I have the impression that playing directly on point 1-2 for move 9, not playing the atari on the first line is also correct and it is still kô.
TherapieGo: I don't find my comments unhelpful, it's just your subjective point of view.
If you want to continue to discuss in private I let you send me a message here -> Therapiego@gmail.com
JN7975: I used the sequence WO3, BN3, WP1, BS2, WN2, BM2, WO1. and then after BP6 it says "incorrect" even though W will now be alive after playing R2.
I appreciate your help, but some of your comments don't contribute. I decided to keep the ko solutions.