Downgrading with jig device

I have a ps3 on the latest 4.31 OFW.

I have a jig device with the lv2diag.self files and the modified downgrade PUP. I remember using this to unbrick a semi-bricked 3.55 when I tried to go back from DEX to CEX and messed up the system.

Will I be able to downgrade to a CFW using the ps factory method from 4.31 or will the ps3 get stuck in Factory/Service mode?

Cheers