You can see if this 4.25 basic MFW install on 3.55 so far i have never tired the MFW 4.25 and ON XMB MANAGER you will have to find one, if you install also i don't know if it will DOWNGRADE or even install. It takes a lot of work and then would not install or even look at the file on 4.10.
Wish I had a flasher and more knowledge to test mfw. I patched OFW 3.15 to MFW 3.15 for my 60gb phat with MFWbuilder a while back, but have been too scared to try and install it in case I couldn't revert back to my OFW without a flasher. (think i should be able to, but wont risk if not 100% sure)
By "after jailbreak", you mean after installing a 3.15 MFW? Currently i use my ipod to jailbreak my OFW 3.15 each time, and the idea of installing the MFW is so that i don't have to use that jailbreak method anymore and still keep my OtherOS.
I assume then i could revert back down to lower OFW without a flasher for any higher MFW /CFW, but what method exactly? Just an update.pup on USB drive in Service Mode, or do i need a special downgrader pkg?
Also, think i've read some about QA flagging in the past, but not sure when it's required. Even with all the reading i've done on here, you can see why i'm hesistant to try MFW upgrade... lol .. need to read or re-read a bunch more old posts to see what i can figure out for sure.
I add them HERE as I run across updates, at the very bottom of that article you will find the PS3 4.70 Keys, Playerkp420-MFW-LV2-FW4.70.bin and Playerkp420_4.70_MFW_PS3UPDAT.PUP from playerkp420 to work from which may be of use.