CDJ will roll it as far as it can be rolled I assume. The YA tube is like a standard tube I assume, which allows for more space. The length of the box (CDJapan) or tube (YA) is no smaller that the width of the poster.
Both will need to be un-rolled anyway, so it's whichever you prefer. Both methods are safe.
You can look at how CDJ does their packaging here:
http://www.cdjapan.co.jp/help/about_cdjapan.html