Aside from they mention high-risk/shady exchange, looks like the tool doesn't consider withdrawal fee & trading volume (only warning message). Cryptocurrency pair on few exchange could have very low volume.
People also need to consider minimum confirmation (e.g. 6 minimum confirmation on Bitcoin roughly equal 1 hour).
Yes, there is no withdrawal fee considers in cfolo. this is one of their Cons.
with small sum of amount , it could make no profit due to of high withdraw fee.