Its as dense as I am, which is pretty dense,,,, and its self lubricating, (like Hesh
JK obviously)in fact,,, in war era construction it was used as bearing material in battle vehicles and gear on account of its being as durable as metal in that function and the fact that it needed little if any lubricating ever!
This would make good sense, in a nut function - as you want free string travel through your slots.... I have never heard of it being used for saddles but I say why not!
Please keep us posted on how this works out for you... I have a large sweet chunk of lignum vitae - the Haitian variety,,, that I was saving for plane construction... however Id consider trying it in guitar construction depending how well it works out...
Im sure it would be a pain to use as a bridge or other applications where a larger surface would be needed to be glued as its as oily as heck and the gluing surface would need to be scrubbed like mad with acetone to remove oils before gluing - Ive heard the same thing, and have had the same experiences with pacific yew...
Cheers
Charlie