I do cut my Choceras a bit on the thick side - New York deli style
compared to the standard sized Choceras so that may help some BUT
Choceras are Magnesia based stones. This gives them the advantage of a silky smooth feel and they are a bit more accommodating than the harder more precise Shaptons -pro and GS. Magnesia based stones (including the 4k and 6k Ume stones, but not the rest of the Nubatama stones) are a bit more prone to cracking - from rapid drying, sunlight exposure during drying and sometimes just idiosyncracies. I look at it as a tradeoff and definitely don't just outright condemn them at all. I still consider the Chocera stones a premium stone. Personally I have never had one (Choceras or Superstones or the two Nubatamas I mentioned) crack on me, but I have had it happen (Choceras) to some customers of mine. It is a rare occurrence IMO.