My gosh! Ebony, purpleheart, Mesquite??? Those are certainly split-prone very heavy materials. Purpleheart doesn't keep it color at all after UV exposure and it a nightmare to
carbide. It is nice and straight. I was looking at some beautiful sticks of it over the weekend, and have worked quite a bit of it myself. There's a lot of old floors with it around
here. Ebony is a camera brand of course, and I own one (though in mahogany). They have
had some problems with end-grain splitting. Need to keep the wood from totally drying out,
with finish refreshment perhaps if the original finish wears off. I've got a customer who just
did over a hundred doors & window in solid ebony - needless to say, the client had a LOT
of money - (that was just for the barn with its seven bathrooms! The guest and main houses are yet to be built!). Mesquite is pretty but very squirrely stuff. If you want another difficult wood that is so heavy it sinks, try mountain mahogany.