I can't help but imagine agents using caveman speak sometimes start behaving in a stereotypically caveman manner, even if it's subtle. Is there a chance the agent does less reasoning because of it?
Training a variant to reason in early modern english in the style of the tudor elites might be an amusing way to test for that.
"Neuralese"
some people made a 'caveman' speak qwen as a joke
https://huggingface.co/ProCreations/grug-27b