I should note that I only tested this on a stock root ME7 build, therefore some partitions that I couldn't flash, the Dev edition of the Gs4 might be able to. I did confirm that users on OYUAMDK were able to flash certain parts of the firmware but no one has tried to completely go back to stock. As expected, I could flash all but recovery, boot, and aboot, djrbliss mentions that the difference between consumer and dev builds comes down to how aboot checks boot and recovery in his blog...so my findings are consistent with his research. I confirmed that the partitions that I did flash were actually flashed because I compared the hexdump of the files before and after (since the file sizes are mostly the same after cutting out the padded zeroes and other indicators). If you have a developer device and you absolutely need to flash stock firmware, this is probably as close as you will get, but more work needs to be done to refine this. Note, take precautionary measures and especially be careful when flashing aboot. Feel free to criticize these, and let me know if any changes need to be made. Use at your own risk and remember this is somewhat a work in progress.
Edit: One user on a dev build brick claims to have flashed aboot.mbn successfully. Status changed to yellow! (Need one more confirmation before I feel confident to give it the green light, pun intended)
Note that this is more meant for a emergency rather than convenience, also the purpose of this post was both to help the owners of development edition gs4 and to make the process better in the future, this can brick your device
If you do decide to dance with the devil, post your findings. The file is in tar.md5.gz format so odin will extract it to a tar.md5 for you or you can just flash it in heimdall. I have left the firmware.xml and pit file in the tar, you can remove them and edit them as needed.
Using Odin: Odin doesn’t play well with this. I’ve had varied results. Use Heimdall. But if you insist..have the latest Samsung drivers, try Odin versions 3.07+, make sure to run as administrator and select/click PDA then select the tar.md5.gz file. Also make sure that only "Auto Reboot" and "F. Reset Time" are checked before finally clicking start.
Using Heimdall: Load the package using frontend running as root. If you use Heimdall in the command line, then you probably already know what you're doing.
I'll tell you my results, from numerous flashes in odin/heimdall. My baseband and build type are both now OYUAMDK as shown below and my phone doesn't show a custom screen nor does my phone think its modified. However this doesn't change the fact that we cannot downgrade to a older kernel. This will not unlock your device if you're on MDK or ME7 and flashing this carries a high risk of bricking your device. When flashing the stock MDK restore, ME7 users usually get a "SW REV. CHECK FAIL: FUSED: 3, Binary: 1" message, however with flashing this on ME7 users will receive a "SECURE CHECK FAIL: aboot" message instead either way its a fail.