They will come out ! Though on the 300/500 you won't be using F40 too often... (Unless it's CAT 3 or very slippery/icy out there or if you have a significant tailwind of course...) I wouldn't worry about the flap load relief too much on the 300/500 mainly because with the landing weights and corresponding Vref's it shouldn't mean a problem. At least I have never experienced it anyway.