I have created additional circuitry in my schematic and would like to update this to the PCB, but only the new circuitry, nets & parts. I’m using KICd 7.0
PCB INFO:
I have modified most of the pads to accept push-in sockets, and multiple foot-prints to accommodate other parts. this is a proto-type PCB that has exotic requirements. therefore, I cannot let the schematic up-date the PCB as it would in its normal operation, changing pads, etc.
PCB Editor / File / Export / Footprints to New Library. Make it a project specific library, and also accept when KiCad offers to update the links to point to your new library.
PCB Editor / Tools / Update Schematic from PCB. This is the other way around from the normal workflow, and it pushes the library links you changed in the PCB editor back to the schematic.
After these two steps your schematic and PCB should be synchronized again, and you can use the normal Update PCB from Schematic. If you are unsure about this procedure, then make a backup before you start experimenting, or do it on a copy, or first start with a smaller project.
I don’t know what is so exotic about your PCB, but the only connection between the Schematic and the PCB are the netlist, some netclass info and the footprint links. And while working on a project, you should never let the schematic and PCB too far apart, and spend a bit of effort on synchronizing and cleanup to keep the project in working order. There is no way to do a partial update of the PCB from the schematic, and the longer you wait, the bigger the mess becomes that you have to clean up.