I've been in engineering, TLM, and management roles in multiple companies. In terms of output, TLMs are not held to the same standard as full-time engineers at the same level, period. Their engineering contributions are dissected only if their performance as a manager is in serious doubt.
In any role, there are some folks who push themselves too hard, and there is no one to tell them "stop", but that's their choice.
In any role, there are some folks who push themselves too hard, and there is no one to tell them "stop", but that's their choice.