8949s are completed for each type (long term, short term, covered or not, etc) of sale, not for each brokerage/1099B.

The top of the input form, it asks for company name, account number EIN. 

If youre importing the 1099B from the brokerage, I dont know it it uses the 1099B worksheet (Ive never imported anything), I thought it just put the figures on the Sch D and the correct page of the 8949.

If you have not imported before, and you start, you will be disappointed. It is a disaster. The program who coded the form should be fired. I have a client with several transactions and brokerage. Several trial and errors, and calling tech support who were not helpful. It took me 4 hours to get everything done. It works if you have one form and one brokerage. 

There is no field for disallowed losses. 

yes

Here is the Help article for Wash Sales:

https://proconnect.intuit.com/community/individual/help/entering-a-partial-wash-sale-information-usi...