CRM 2013 Remove Locked Field in the Header

Sometimes, when you work with Quote or Opportunity, you are going to replace some field in the header to other fields that is more important and necessary for your customer business information and analysis.
Here, I give Quote as example.
My customer seems does not need the “Effective from” and “Effective to”

Those fields actually can be replaced to other fields, such as Total Discount, Price List or whatever more informative field.
Then, when you try to go form and want to remove those two fields, you would be given an error :

Then, you are aware that that fields cannot be removed, so first what you can do to fulfill what user wants to see more important field in the header is by adding that fields into form, like that :

Then, you publish it.
Well, it will work, but you will not be longer to see that default header tiles that more beautiful in this Quote Form, because when you see it, your header would be having 6 fields, which is more than 4 fields, see this :

Then, where is that beautiful header tile?
Okay, please take a look in the header at form editor when you add new field after that 4 default fields, there is a warning block :

Then, you try to manipulate the screen by doing un-thick the visible by default, before that you move down those two fields to the second row :

Then, we see the result, can it?

Okay, that seems better and looks simpler, rather than having two columns, congratulation you have done the user request, to show the Net Selling Price and Price List fields that they feel are more important.
But, you also want to cater a good UI for them, right? Then how?
Okay, this is the resolution :
1. Add those two fields into a section (later you can hide the section if you really do not need this section)

2. Then go to Header, then now look, you can remove those fields, then that warning block was disappeared now

3. Then publish
Here you go :

The conclusion is :
As long as you have the field in the Form (Header or Body – not applied for Footer), you can remove the field from another area each other. To control your header UI as tiles type, you should have no more than 4 fields in the header, you cannot use the ‘visible by default’ method to reduce your field number by hiding it, but in the body, you can control easily.
I believe this will also work for other Updated Entity Form that can have header tiles, such as Opportunity and Order.
To know what entities that its form has been refreshed, you can refer to this table :