Hi. Thanks for your submission. I prefer #32 because has some color. I find #21 and #22 interesting but they're very dark. Can you try to add some colours, please? The place for the symbol is rather irrelevant at this stage. I will use the logo and the symbol in multiple position combinations.
#65 is my favorite. Please try to make the F more visible. Or maybe remove the F and have the K completely upside down to have the flip feeling. #64, #66, #69 are fine, but I prefer all the other ones.