Yes, it needs to be filled. This is a matter of common sense. The state of the original mold will affect the surface effect of the molded FRP mold. Don't think that the mold still needs to be polished, you can match it seamlessly, as shown in the picture above: originally you only need to simply fill the butt joints of the rtm wax sheet, but now you need more time to deal with this bad situation.
For the butt joints of the RTM wax slices, you can use plasticine or filling wax, etc., which can be used for temporary and effective treatment, especially in some corners of the original mold, you need to operate carefully.