the extract-files.sh only cares about paths - if you provide it either adb root (via twrp) to the running rom, or a base directory that you unpacked the original stock rom zip into (or any old lineage zip), it will copy over what it has listed in its script. The script itself is usually with the device vendor. The latest xda threads on the device point to github repos that has them.
I recently made a build for j3xnlte that is very similar to the j3xlte - just a different kernel. The repos are listed in the linked roomservice.xml - [UNOFFICIAL BUILD] Samsung Galaxy J3 (2016) (j3xnlte) - e-0.21-n
if you’re not keen on building yourself (as a learning exercise) I could make a j3xlte build for the old e-0.21-nougat (I tried to go with updated apps in the /e/ 1.6 branches, but too much errors, easier to rather remove them).
(the pmOS build uses the old 3.10 kernel too, there are no active mainlining efforts for the SoC)