I think on the whole, the machine will always be far enough away.
I’ve got a two stroke hedge trimmer, never once has it given me any headaches/nausea etc.
I think it’s very rare. Think of the amount of people using petrol/2 stroke machinery each day. 99% of the time there are no Issues.
Common sense is needed, but being over cautious isn’t helpful, it just causes anxiety and fear.