No a common practice in my neck of the woods, typically the make up (street) water, goes through the filters,softener and to the condensate receiver. I wouldn't put raw,untreated water in,and wouldnt pipe it directly into the boiler for the obvious reason.
Thats a great point that for some reason I overlooked. But true that I am dumping "untreated " water into the boiler. Although Im sure it is not there long before it is "diluted" with the treated makeup.