Dan, I think you are cherry picking, and interpretating things
on Ilford's site to suit your own technique or view.
Ilford list a number of different, all valid options for
fixing and washing fibre papers on their pdf page at
http://www.ilford.com/html/us_english/pdf/95065d.pdf
Ilford recommend short fix times in Rapid fix (that's 1+4
for one minute). They also recommend the use of a wash aid.
They also state that the rapid fix (1+4) system is good for
40 10x8 prints per litre.
Rapid fixing for me is the way to go. It's simpler, it's more
efficent and it makes washing much easier.
Having said that there is no absolute correct way to do
things. Work out the way that best suits your set up.