Yes, blackra1n RC3 patches your commcenter file to allow any ipcc/mobileconfig.
And no, blackra1n does not provide a method of upgrading without upgrading your baseband; you need pwnagetool for that.
blacksn0w (part of blackra1n) *does* unlock the latest baseband, however.
Personally, if you need an unlock and have an older baseband, I'd stick with it and make a custom ipsw with pwnagetool to upgrade. No need to lose your safety buffer unless you have no other options!
My iphone is factory unlocked so I want the new baseband.
It seems better on signal, but anyway the signal strength works and any sim I put in I see the name and signal.
I had to patch the CommCenter on my 3GS, it refused to tether, so it was still signature checking the carrier files (I patch them myself). As soon as I patched the CommCenter and rebooted presto I was greeted with a internet tethering in the settings.
Anyone else experience tethering issues on a 3GS I suggest patching your CommCenter and you will be fine.
My 3G (also factory unlocked) seemed to be okay without patching the CommCenter. I patched it anyway as the file was a few bytes different in size and it seems stable enough.
I think the patch for the 3GS is wrong or not being applied properly.