Thank you Austinwatson22 for your reply.
I'm afraid my post was a little ambiguous.

What I am complaining about is the waste space at the bottom of the screen on the Kobo with the present firmware. I would like the pagination at the bottom for PDFs to be optional so that you can remove it and use this space for the PDF.
For a PDF, the fact of reducing the height of the page has the disastrous effect of reducing the width (since the PDF page itself is of fixed ratio) and thus you end up not only with a space at the bottom (for the relatively useless page numbers) but TWO blank columns on the sides (even more waste space).
Consequently, for a PDF which otherwise might have been easily readable, you have a tiny page which is hard to read and lots of waste space !!

Sniff!
Rojofo.