I've written a report about worlds over 100mb failed toto copy. This is when I was trying to activate Experimental Gameplay to a world which is only 53.4mb. Once activated the world should be copied and the poriginal woold is left untouched. That isn't the case for me when I tried to do so it entirely failed to copy and add experimental gameplay. I wanted the lamp for a map I'm still constructing, and with the new features coming I'm hoping I won't need to wait for the next update for the official release of these features. I believe the copying system needs to be fixed for you can't copy worlds over 100mb. Now it fails toto copy worlds over 20-30 or more mb.