There is no need to enter a hashrate limit for CM at NiceHash. We tested it sucessfully with 30GH. However, NiceHash lets you pay about 15% more (delta) for each order, to reward their miners for the high amount of CM coin switches. Please take this 15% into account for your profit calculations.
I can see now that the statement is true.
I like the CM UI but I gotta point my hash to somewhere else where I can make a profit.