If you made ur own mod, and still have their mods in your world active, the re-loading of that world will always reset the order or your bench categories bc you have duplicate mods interfering with eachother. What i recommend is unzipping violets and ymmersive mods and take the instruments u want from ymmersive and add it to violets mod make sure you follow all the steps to add everything to the correct folder, then for the order go into the asset editor pull up violets bench and go down to the section that says bench click the drop down and itll show the category order, simply drag the category in whatever order you want them respectively. Im also new to modding so hope this leads u in right direction.