What to do about the knot? It depends on the intended width of the bow, and how the knot runs toward the belly. Does it go straight down or at an angle?
If it goes in at an angle, then slicing it off the edge will looks like it might get rid of the knot , but all it does is expose the knot on the edge of the limb. If you have already sliced the other edge to the ideal intended width, then you are left with a weak spot, which could cause issues in a highly strained bow. If the bow is overbuilt with its design it might not be an issue.
When I have a knot like that, I initially leave that area wide enough, so I have the option of being able to change my strategy on how to deal with it, as I get a better idea of what the knot is doing as I remove wood.
If I can't totally avoid it, then I will leave a swelling around the width wherever is appropriate, so that there is the same amount of wood
as a clean stave, plus the width of the knot. Some guys don't, and they get away with it. Some guys don't and they end up with a broken bow. Leave enough clean wood to do the work, then its not going to break because of the knot.
That is a superfine stave if its plum. You probably won't come across a stave like that very often. Personally I would leave it for a while until you get more confident with the process.
Plum has a reputation for checking whilst drying, so I wouldn't rush things or leave the back unexposed, if you take off the bark.
