I've not put the string tree on it yet as it didn't seem to need it and plays very well. I've put a tree on previous "fender" type headstock builds. However I think I will add one for completeness this evening as although it is playing nicely, I might well tinker with the nut and action in coming weeks and suspect that whilst it seems not to need a tree now, that could change. Unlikely to have any adverse effects anyway.