Keep the good work :-)
Thanks very much for the feedback, it's really appreciated.
Hmm yeah that would seem to be the ideal behaviour for sure. I just gave it a go and it seems you can rearrange downwards but not upwards and also not as you would wish. So if you drag something down in the same column it will go to the end of that column. This definitely isn't ideal. I had initially started implementing using my own draggable implementation but then reverted to using html5 draggable with contenteditable. I ran into some styling issues when dragging items whilst trying to remain responsive. Basically the items were styled at 90% of the column width but when you dragged them out they grew to 90% of the page and then shrunk back again when they were dropped but I was unable to hack the drag move in a way to maintain size without there being some jump in width which I didn't think looked pleasant.
This could certainly go down as an issue if you would like to add it or I can add it to the repo.
I'll try to keep it up and thanks again very much for the feedback, it's really appreciated!