My infill plane has a 3/16" iron, carefully bedded to give full support. Bedding angle is 49 degrees. Mouth is gaping like Kerry's, mentioned above. With some shims I can close it to about 0.5mm. It's a nice performer, but certainly not immune to tearout. Even something mundane like oak against the grain will tear.
Once I did a bit of testing with several setups to see how they perform to prevent tearout in a misserable piece of maple with some strong grain reversals. A 0.3mm tight mouth wasn't not good enough. Only when nearing 0.1 mm I was getting a smooth surface. This was with a Stanley plane with Ray Iles iron. A well bedded thick blade in itself will never be good enough to prevent tearout. You need additional help like a very tight mouth, a higher bedding angle or a chipbreaker set very close to the edge. Even an infill has to obey to the laws of nature.
But we don't need to tell this to people who don't own an infill of course. :lol: