I hope I can help you somehow. Since I am not a developer I can maybe share my ideas and templates (see my post into category “templates sharing”).
My first idea is about linking to each Invoice Family a different Invoice Template.
Why? Let’s make an example.
Let’s say I am a Hotel Manager… or Accounting Manager for a hotel.
I work both with consumer users and travel agencies (or tour operators).
At guest checkout, if the guest is a consumer user, I need to make a receipt for b2c. For this receipt I can only print the gross amount (or amounts). I do not need to particularize the tax rates (tax-rateS - plural - it not a typos).
On checkout when the guests have come to me through a travel agency (or tour operator) I need to issue an invoice for b2b to the travel agency. This is pretty different than the b2c receipt. Now I need to particularize for each service: net amount, tax rate, tax amount, gross amount… why not, even the discount for the travel agency. Each service has usually a different tax rate than the other services in the same invoice. The cost for the room has 10% tax rate. Laundry service has 22% tax rate. Room-frigobar has no tax rate but food and beverages taken at the hotel-restaurant have 10% tax rate.
Ok I do not want to bother you any longer.
I hope you find this subject will be interesting for you.
Thanks for you time
Kindest regards, gsolina