Hopefully someone will come along with more factual info. I believe you can operate all of your DBAs under the same EIN. You can also add DBAs to your DUNS. This leads me to believe adding your EIN and DUNS to your profile with the creditors that are not reporting will eventually clear things up.
Yes, its kind of a process: https://www.equifax.com/business
You will need the name of the financial institution you'd like to add, your username, and password to get started. You must have access to your account on the new financial institution's website to link the account into the Member Center.
In the Equifax Member Center, select My Account and then the Alert Preferences tab. Expand the appropriate section--Banking or Credit Cards--and click on the Add a New Account button to begin.
If the Add a New Account button is grayed out, you will need to remove an existing account to add another new one.
You can add a new account under the parent company that is reporting or in which the DBA is tied to. However, if the FI is not reporting the item to equifax then it will remain an un-scored item but show the account on the report.
https://www.equifax.com/business/business-risk-monitor/
It appears to be down for new clients while they revamp.
I believe you can do it from a MyEquifax account which should be free to sign up. Click on login and it will give you several options to choose from. If you have all the information available you might be able to have Rep do it by calling in.