Yes, I do print to PDF. And remove (or rather don't print) the two unnecessary pages out of the six. In fact I'm a complete non-paper user where possible (and in countries where I've been asked for paper copies of tickets etc I've never had a problem explaining I don't have one and proffering an electronic copy instead. Not that I'm saying it never causes problems for others, of course).
But I know the accounts department of my client prints paper copies of everything for their archives, and have commented that BA receipts are a PITA in this regard. They're not interested in how I might request a special meal, or what to do when I get to the airport etc. And frankly, nor am I. I just want the details of my flight confirmed.
I also had to explain why a middle page was missing when I first submitted a receipt this way. It really shouldn't be necessary.