The thing with cordage is that tasks like shelter building and lashing use up a lot of it. So you need a fair amount.
I tried carrying 100' and 50' lengths of paracord, but hated having to unravel it each time I wanted to use it.
10-4 on that. One option is to stack (not coil) the cord in a 1 quart or 1 gallon ZipLock bag. When you need some just pull out what you need and cut it off. No tangles, no hassles, and it packs flat. Pre-cut lengths of a useful size, like you mentioned, are a good move too.