Cast iron surface plate scraping part 2 radiused vs flat blade HD

For push scraping, I have learnt that you shall use a radiused blade. The flat blade will increase the likelyhood of scrathes, especially with the BIAX power scraper. I only found that I could do the circle technique with some degree of success. I try to show a little on this topic and how my scrape marks looked flat vs. normal blade. Correct angle is also important as i downwards pressure and not tilting the blade when moving sideways ie. always keeping it flat to the surface