That said, using the Chameleon with a (even partially) broken C64 is neither supported nor recommended.
Other than the SIDs being partly defect the C64s are in very good health. I even recapped them a week ago. I have also measured the voltages coming from the power supplies, and found them to be correct. Also waiting for an overvoltage protection unit I ordered. And also a modern power supply. So I do not think these partly defect SIDs would do any harm? I just find it really interesting the TC64 V2 takes full advantage of these partly defect SIDs and sounds perfect when using the 3.5mm jack from the TC64 V2.
But I understand where your coming from as an icomp developer and with regards to support.