I mean there is nothing new out there to my knowledge.
Also, why a DUNS?
Paydex/Bussiness credit though is different.
Get a business credit card, and use it, same rules as personal card. However make sure its a true business card, may business cards are really personal cards with your business name on it.
Capital One for example is not a real business card, as it reports to personal credit, not business.
Next, acquire and use tradelines/net 30 terms.
Some companies offer those predone for you, theyll add the tradeline with history to your file.
Cant hurt to reach out to one of them and see what kind of plan theyll put you on.