Years ago (in the days of F & Y only) I had a friend (of normal weight and size) who received his travel allowance in cash and was permitted due to his position in the company to fly F. What he would do was book two seats, window and aisle in Y thus guaranteeing no-one would sit next to him and giving him enough extra space for his coat, papers and that extra bit of comfort. The saving over first was still enough to make it worthwhile and allowed him to pocket some extra (taxfree) cash.
It seems this is no longer allowed and Ryanair bans it altogether though digging through Easyjet’s site it seems it is possible under certain circumstances but you have to call them, it’s not possible to book online. In theory this would give you double baggage allowance (which in some cases would make it cheaper than paying the excess charge) and I suppose if you book two seats and check-in online you would perhaps get away with it.
Has anyone tried this and what was the outcome I wonder?