I could be wrong but I don't think the synthetic winch lines are nylon, and I've also been told to never use a roller fairlead with synthetic line - always use a billet aluminum hawse fairlead.
Nylon is the material used for "snatch" or recovery straps - the type that stretch when loaded, polyester is what's used for tow straps and winch extensions, so my guess is a nylon winch line will stretch, which is not quite what you need. The commercial products are dyneema and plasma
Front end weight is also a concern of mine and I have been considering, as you are, a synthetic winch line as an option to reduce the additional weight..