I used to always rub my flakes out fully but once I 'got' the folding method I have never gone back to rubbing them out. The secret to the fold and stuff is to not take the 'stuff' part literally.
What I do is I take 1, 1 1/2, or 2 flakes depending on their size and the size of my pipes chamber and simply fold them in half. Then I use my thumb and first two fingers to gently roll the flakes to encourage them to break up a little into what looks like a little bundle of firewood sticks I'm going insert into the stove (my pipe).
The key is to size your little bundle of firewood, with the 'sticks' all roughly oriented parallel, so it just fits perfectly into your stove without having to compress it, or with very, very gentle compression. You want the pipe to be full, but with basically zero resistance on the draw.
If you've ever made a campfire, or used a woodstove then it's actually incredibly intuitive what your doing.
If the flake stick bundle is too long and sticking out of the top of the pipe, just pinch the excess and tear it off, if the bundle ended up a little short I just grab a little pinch of the bits and top it off til I'm happy.
Like I said the pipe should be full but with no resistance to the draw. Because flake tobacco is compressed and is denser than ribbon you must give it a bit of room to expand or about halfway to bottom the bowl it will be too tight and you won't get a good burn.
If you load your bowl right and tamp gently the bowl will usually burn right to the end with almost no relights.
Since switching to this method I don't even have to worry about moisture levels and drying anymore, even the wettest gawith flake straight from the tin will burn just fine (once you get it going).
Mac Baren flakes are probably the easiest to learn on since they are so consistent in size, but once you get the hang of it, it's easy with any flakes no matter how rough they are.
It's way harder to type this out than to load a bowl l. it's really a super easy way to load a pipe, I think by far the easiest and quickest, even easier than loading ribbon.