One of my kids had one of her AP hs classes structured this way. She found many of her classmates had issues managing their time, and didn’t even begin to take the material seriously until after the first try on the test, when they would then address their deficits. On the positive side, there was absolutely no stress in the class due to unlimited opportunities to improve; on the negative side, it did not remotely prepare them for any actual college course, and I do not know how the class performed on the AP test.