Ok, I better report back. After scratching my head in confusion as to why I couldn't seem to get the aud_clamp method to work but it was still booting ok with the original wiring with a supposed aud_clamp type image flashed on, I had since left the power disconnected for the past 24 hours.
After coming home from work today I had a new image built ready to flash on that had been built with jtag tool using the aud_clamp only method, same as what I'd done using Easyfreeboot.
Guess what happened upon booting..........E79. Weird, I thought, I've never had an E79 on this console before!?
I still had the original wiring in place but also noticed a quick "bip" sound through the speakers that I'd never heard before. Instantly I thought, ah that's new and the only difference is that it's had a proper power down and reset.
I grabbed my soldering iron and swapped the TMS wire from the ROL to the aud_clamp and wha-la.....it booted clean, so by failing to remove the power and let the console fully reset I hadn't let it enable the new SMC configuration that I wanted to switch to.
I feel like such a NOOB
I thought "What the hell!" and went ahead and also flashed on the image that I had ready, built with Jtag tool using the aud_clamp method also and reset the console properly this time, too.
No problem there either.
My absolute apologies to the developer for thinking that it was something wrong with the app and I hope this might save someone from the same headache.