The SLE15 development model follows the Factory First policy, where all submissions need to go first to openSUSE:Factory and then to SLE15 repos. This way more bugs are fixed, less patches get lost, less backporting is happening etc.
Our openSUSE infrastructure is using salt for configuration management. This was working fine, but suddenly we had to split the openSUSE from the SUSE-DMZ services into separate VLANs, thus the salt codebase had to be split as well. The code itself is mostly formulas and quite similar states between the two set of services though. The only real difference was in the pillars, and even there there was a lot of duplication.