The thickeness of your card has no relevance to the test, as you’re just ensuring that all points are the same distance to each other. The instructions don’t say to use a card, just to look at the nozzle and raise the bed up with the knobs until it just touched the plate. I did this by eye. The level sensor will (should) take care of the rest. Looking at your results, it looks like you need to clean your plate more than anything, as it’s failing in the same area. The engineering plate seems more ‘slick’ than the high temp side to me. I would clean and dry it well, flip it over and use the high temp side for your next attempt. If that doesn’t work, I don’t know if you can reverse it and start from the back corner first?