Currently, Fast Dial will allow multiple pages beyond a certain predefined number of boxes
Is it possible to customize that and define ourselves how many boxes we want on each page

Please could you clarify your question

Are you talking of the fact that Fast Dial if you scroll down the page starts a new page ?

I am under the impression that if you set up your fast dial to have for example a page layout of 3x7 then the new page will start after 7 horizontal lines.(if you have more that 7 horizontal lines)

Or this is my impression

So if you wish you can increase the number of horizontal lines to 30 and your scrolling page will start after 30.(that is if you have more than 30 lines of cells)

Is this what you are referring to ?

many thanks