In the past we only allowed you to have one default subject line for all your quotes, with the ability to modify the subject line in the draft quote view. 

Now you can set your default subject for each template, and add a separate BCC. You are also still able to modify the subject line when drafting a quote if you wish.

You can also add template variables to be used in the subject line. Full list of template variables here. 

The more popular variables used for the template subject lines: 

{{=quote.quote_id}}
{{=customer.firstname}}
{{=customer.lastname}}