Unfortunately, if there is any discrepancy in how the cards appear from the back, I as a tournament host would have to rule them illegal. So if normal-sized cards poke out, but I/J sized cards do not, I would not allow those to be played. The recent run of the I/J/Tin 26 cards are normal-sized however, so I would ask around your playgroup to see if anyone has normal-sized copies of the cards you use, and trade for them. Alternatively, you could snip the tops of the cards you use in that deck, assuming you plan to keep that deck for awhile and don't intend to trade/sell the cards.
