So, got a QSO in the log and the good news is the AGC seems to largely work, particularly on Rx.
However it has introduced a very sharp tick at the start of each dit and dah on Tx.? This is very different to the clunk that was present before and sounds more like a loud spark if that makes sense.? I have turned AGC off and can confirm this artefact goes away...
73 Danny M0SDB