Build own Firmware (GL-E750 Mudi)

Hello everyone! I have a GL E-750 that I’ve meticulously customized to suit my needs over the past few months. For instance, I’ve set up an automatic VPN switch every 4 hours, among many other things. I’d like to package all these customizations into a single “.ipk” file so that I can conveniently install my customized system using U-Boot. Is there any way possible to essentially “clone” my system into an .ipk or similar format?