A user by the name of "kmeaw" on IRC channel #ps3test has made it possible to run Backup Managers on Wutangrza CFW.
Basically it's a simple PKG you need to launch before running any backup manager. It will patch lv2 and add syscalls in memory. They are removed once you power off. Safe and efficient!
First run the PKG, then run the Backup Manager. When rebooting, you need to repeat the process.
More info (instructions): PS3 CFWs with backup managers
UPDATE: Source code for developers has been released HERE.
Disclaimer: This package is for demonstration use only, or for running your own made software (homebrew). We do not condone piracy and are not responsible of the small chance you may brick.
Original FW PUP md5 before patching: ca595ad9f3af8f1491d9c9b6921a8c61
Patched PUP md5 after patching: 2be5e87a22bf1e7f48e98fcabd38977b
If you are on Wutangrza+geohot fw, you dont need to flash the new firmware, just install the package, and run it every time the ps3 boots before running apps that need PL3.
Otherwise, it is suggested that you upgrade to 3.55, Upgrade to this patched PUP, then install the lv2.pkg.
This is only until apps are updated to include this patch themselves, as then you wont need to run the patcher on every boot.
For Stock ps3's
1. update to official 3.55
2. bspatch PS3UPDAT.PUP PS3CFW.PUP patchfile
3. Delete PS3UPDAT.PUP
4. Rename PS3CFW.PUP to PS3UPDAT.PUP and that's it! You're ready to install
5. Install lvl2.pkg
6. Launch backups with managerkmeaw's CFW is different from FLUKES1 and Wutangrza and anyone elses.
Basically kmeaws CFW has peek/poke, and the same patch that Geohot released, along with access to app_home. app_home is used for diskless booting of your games with a BM. Please refer to your BM's thread for how to boot diskless. You will need to reinstall any of your homebrew/backup managers with signed for 3.55 or signed w/ debug keys for 3.41 copies.
Wutangrza's CFW is basically what flukes1 released it just has peek/poke enabled but you can't install PKG's.
Geohot's CFW can be installed over the top on Wutangrza's CFW and allows you to install special signed PKG's.
This LV2.pkg patch can be loaded from any CFW that has peek/poke, and adds syscalls for backup managers etc.
1. the "3.41" PKGs, which are debug packages. They're not signed, so if you try to install them on geohot/waninkoko/OFW you get a 80029564 error.
2. Geohot 3.55 PKGs. These are "retail signed", but not in the same way as some PKGs, so you'll get a different error if you're not on Geohot or Kmeaw.
TLDR: You can install BOTH kinds of PKGs on Kmeaw, but if the 3.41 PKG's EBOOT.BIN hasn't been properly signed[if it's a really old homebrew nobody's updated yet for example], you'll get a different error: 80029561 I believe it is, which means the EBOOT isn't retail signed.
Thanks to PSX-SCENE user bigheads for the news tip! And thanks to daxtsu for the better explanation of which packages work for which firmwares.