There seems to be some misunderstanding about the purpose of Transparent’s cable recalibration. There is no need for periodic recalibration. The purpose of the calibration or recalibration is to match the output impedance of your amplifier. So the only time you need to recalibrate is if you are changing amps and the new amp’s output impedance is significantly different. For the Reference cables there are two versions, one for high output impedance and one for low output impedance. There is no cost for this if you are the original owner. As far as potential damage to your amps, I have never heard of that.
Transparent cables Recalibration prices out of this world
If you are not the original owner, prepared your wallet because depending on the model do you have it they charge up to $1,200.00 plus shipping cost both ways just to be recalibrated. I understand they have to charge it but boy $1.200.00 it's insane.