Yes it does pattern blocking very well! As a matter of fact I guess you were the one who suggested this app to me long back! I have already mentioned the link to the original discussion in my reply to OP.
See the screenshot. It has multiple ways of blocking numbers. One small observation I have is that it's better to put number as well as number preceded by +91 for better results. e.g. if you are receiving spam calls from say 120 123 xxxx then better to put 120123? as well as +91120123? as a pattern in the block list.
By disabling Notifications you can put the app in total silent mode. However I am not sure if this functionality has been modified by the developer now.