Remember that LED headlights whether they are replacement bulbs or legal dedicated lens integrated LED units will draw half or less current than OE halogen bulb draw. Added to this is the fact that LED headlamps will work at 100% through a range of voltages. The advice on fitting a relay with such will likely offer no advantage therefore especially as volt drop is proportional to current draw. It will however be counter-productive given increased likelihood of unreliability from extra connections.
As I've said before generally electrics benefit from simplicity or applying
KISS principle.
Worth bearing in mind that most dedicated LED headlamps incorporate some form of higher power sidelight or DRL function which when used give safety benefits in terms of visibility during daytime driving.
