Well to my knowledge the majority of modern ESUs monitor return current to ensure that excessive leakage is not a problem. Some floating ESUs also monitor plate voltage, if it starts to float towards excessively high voltages, to avoid large potentials on the patient. There's split plate monitoring to ensure good contact with the patient and return lead continuity. On some ESUs there's also means of monitoring any imbalances in return current across split plates so that the even distribution of return current is maintained. So I guess the issues that I've been raising are of enough concern to the manufacturers at least. What you're saying makes sense of course - the safest and simplest option is to get the manufacturer involved - that's the advice I suggested way back in the postings.
