For some reason, currently you cannot make signs out of this mod's wood. For example, you cannot make a Fir Sign or a Willow Sign. Seeing as other mods that add wood types of their own include variant wood signs, and also seeing that such a feature exists in vanilla Minecraft already, it would make sense to do so.

Also there should be boats with variants as well

A duplicate of #1633 but I agree. And it's not quite hard to add actually.