Lovely mod! Makes building a good looking log cabin a breeze- having to chisel a house worth of logs to shape would be a nightmare!
Some suggestions for stuff I'd like to see would be a vertical variant of the log slab, and bark-stripped logs. As there's a texture in the game for bark-stripped log (you can see this when you remove a layer of bark from a log with a chisel), this would hopefully be something easy to implement!