All our stuff is targeted to be as high of a firmware as possible (which at this moment is 5.4.0), Hykem's just on a lower version for the moment because there is proven stuff on that version that he's using to get info for the latest versions.
I'm hoping that you'll keep the lower versions supported as well, especially with Hykem saying he's back-porting to 2.x.x on the previous page (and 3.x.x aleady done) in particular in case an emuNAND becomes possible, or a way to (relatively safely) downgrade is found in case that's needed for the IOSU exploit (which likely is needed to have low-level access to the SD card for EmuNAND)?