Glenn, the lumber that you buy will have the corners eased. Unless you are planning to plane the faces of the wood, you should have broken corners. I would not suggest trying to do anything on the table saw since trying to handle relatively long and heavy wood is usually an invitation to binding up the blade.
You can get a wood bodied radiusing plane for around $15 but I don’t think you will accomplish much with one of these and your larger timbers. You can also use a block plane to do the same thing in more passes. There are some small planes available at the home centers at low prices but they do take a lot of fussing to get and keep them cutting well.
Henry in MI