Flashing from OFW to CFW

Hi all! Sorry for my english at first :)

When latest CFW was 3.55 many people needed to downgrade from 3.56+ on 3.55, because console (due to flash) warning that new fw need to be 3.56+ or highter, right?

But now latest CFW is 4.30. Why I can`t flash my phat ps3 4.10 with 256 nand via recovery to CFW 4.30, what will be - brick or something else?

Thanks!