While I have yet to try I believe that doing a vertical miner setup with the S3+ Units would also improve cooling. Warm air exhausting directly upwards at floor level will result in the least amount of exhaust air being recycled back into the intake as warm air rises all on its own.
Vertical airflow sucks for actually dealing with that heat once it comes off the units, so unless you're in a multifloored data centre with floor to ceiling airflow, you're just making it more difficult to expel that heat. At least with horizontal flow you can then DO something with it, ie move it elsewhere / outside.