add bitcrabs comment

bsip-0042.md

@@ -153,6 +153,10 @@ Witnesses should make their own decisions on whether to set a hard limit and
 how much should it be if need to set one, generally, to reduce impacts caused
 by bugs.
 
+It will be good to apply the change to bitCNY first, which has much better liquidity 
+than other smartcoins. After witnesses and community learned enough in the process 
+it can be also applied to bitUSD.
+
 # Discussion
 
 - https://bitsharestalk.org/index.php?topic=26948.0