As the title stated, I have upgraded to official 3.1 by mistake, but was lucky enough to have 3.0 ECID hashed on Cydia and was able to downgraded back to 3.0. Now as it is, I'm on a JBed 3.0 with baseband 5.11(this probably doesn't matter), and since a JBed phone should accept a custom FW, can I upgrade it to a 3.0.1 custom?

Just curious of this as there's close to nobody in the world who has a ECID 3.0.1 hashed, but if we can downgrade to 3.0 and then upgrade it to a custom 3.1, then there's another option to those lucky 50,000