PW3 Can PW3 5.15.1 be jailbroken using the serial port hack?

I have a Kindle that I bought already on a high firmware. It's been sitting on my closet for a good while now.

I know that in the past you could hack Kindles that were above the softmod firmware limit by disassembling it and using a serial interface found in the motherboard.

I wonder if that'd be possible to do this if you're on 5.15.1

Thanks.