I think it would be amazing if you could add back all the slimefun machines! If not Atleast add the automated gold pan in basic machines jetpack auto gold pan I, II, and III in energy and electricity Auto Ore Washer I II and III the other capacitors, and solar panels
The reason not all the SlimeFun (SF) machines are in the server is because many of the SF machines could cause severe lag that would ruin other players experience. Another reason why so many SF items are missing is that they are way too op and anyone who doesn't make them will not be able to keep up with others. Wouldn't mind the auto ore washer and another generator though.
If there are specific things you want, list them like @Alguy1 did and we may be able to consider them. It really comes down to the impact they will have on the server.