Performance Metrics

Hello
Does anyone in the community have any idea how to generate 'custom performance metrics' in RapidMiner? I'd be grateful to know.
The list of metrics ("recall", "accuracy","F1 Score", etc) does not include "Balanced Accuracy" or "Balanced Error Rate". Yes, I can manually calculate these, but there must be some simple way of generating them post execution?
ChatGPT and CoPilot suggest using the "Generate Attribute" operator, but it fails to recognise the metrics mentioned above. Wasted ages so far trying to achieve this. 😓