6b is also no longer special cancelable, frametrapping with Tsunugui or SoD won't work in CP.
However, you can chain into 6c and steins on block, 6c being the most powerful option, as 6c stein cancel is completely safe and nets you a stein advantage. 6b's push on block is also very much increased, which, when combined with 6c's decreased horizontal minimum range, means that so long as they don't IB the second hit, it'll be hard for them to avoid 6c. The gatling has roughly a 2f gap on block.