Nial.
Friend of mine who flies B767's as first officer showed me the B767 checklist. I compared this with our flying school checklist for the Seneca and the Seneca had double the checklist items more than the 767. We still use FREDA , TEMPFISCH, PIST, EFMOST, on the Seneca so it seems to me that if the airlines used mnemonics they may not miss so many checks as you mentioned.