Really simple for a complex problem, but any possibility of making smoke from gasoline/diesel engines emit from the closest muffler away from the frame, instead of just in a set place based on how the frame is constructed?
If you really need to, you could use pipes to lay combustion piping to connect to the muffler, and using multiple mufflers could dampen the sound? Not really necessary though.
Seems kinda silly that, let’s say you’re making a base generator, you can’t plant the muffler in a jut that pokes outside and expect the gas to go out that way.