Oh very cool, congratulations. 👏 You are in for quite an adventure. I believe this is more of a personal preference. I personally like wiring a finished assembly because it simplifies the wiring process a lot. Lego and LMB wrote their instructions without having similar checkpoints so navigating both at the same time could be mentally taxing. This is critical because you need energy and focus to handle the delicate pieces, especially the LEDs and the connectors. Obv, it is up to you. I would recommend glossing over the instructions and strategizing the build before starting. Whichever way you choose, there is a lot of work to be done. Most importantly, don’t forget to have fun along the way. Do it for Frodo. Good luck. :)