DevUnlock actually allows only to deploy XAP files from external sources.
It doesn't give more privileges.
So we (DFT) developed "FullUnlock". FullUnlock is implemented as
replacing some system files by wrappers, which allows any kind of access (disable access checking at all)
We replace LVMOD.DLL which used to check files and data (checksums, certificates and etc) and POLICYENGINE.DLL which implements internal objects access checking.
All written before means that FullUnlock at the current moment
only possible by flashing custom ROM to device. In future maybe we can find good ways to do it without flashing, but for now I don't see any ideas how to do it without flashing.
Maybe we can replace DLLs inside \Windows\ directory (put a shadow copy), but I am not sure if it will work really. It's stuffs for future experiments.
It can be possible to do something near by editing policy values, but it need big research to find right way. As it still won't disable file checking, maybe we can add own certificate to right store and then sign files with them.
The last DFT 7720 MANGO ROMs contains FullUnlock, but it doesn't work as expected

there few issues. as well some users got issues with debugging on those ROMs and etc. We will continue work under it