wrtboy: I'm not sure if you're looking in the right place; LEDE splits out the regular packages (most userspace stuff) from a few core libraries and the kernel modules, the latter two ending up in their own directory. Maybe that works similarly in the image builder as well?
Either way, I have migrated all my deployments last night after a testing period and everything I needed was there, same as on OpenWrt. After all, LEDE still uses the OpenWrt package feeds. So I don't know which packages would be missing.
Edit: basically what hnyman said for the first part
(Last edited by Borromini on 23 May 2016, 14:52)