Mediterranean harbours are littered with fairleads, not just from Bavarias. After a blow at Vathi on the Methoni peninsula in Greece a few years ago, a diver on the boat next to us picked up 4 fairleads from 3 different boats.
Fairleads are not designed to redirect the mooring lines, merely hold them in a fairly straight line. Ricd is correct about the forces. If you have the line doubled back, the force on the fairlead is doubled. If the bow lines need to go back on the dock, tie off to the cleat on the opposite side of the fairleads to reduce the angle. I'd much prefer a fairlead to give way than have a cleat pull out or damage to the hull if the screws did not give way.
Bavaria position the fairleads correctly in relation to the cleats for Med Mooring, bow to mooring and for the mid ship line to hold you onto a pontoon in a blow off situation. For usual side on mooring, ignore the fairleads and run the lines over the toe rail. They are smooth enough to not chafe the lines. Snubbers are essential if any wave action in the harbour is expected.
Craig
"Shirley Valentine"
Gold Coast
Australia