Garrison Sove V (coal and wood burner)

The manual does not answer my question and as I have not used the stove for some time I am not sure I remember the answer to this question. In the top of the stove is a heavy metal plate that slides from the back towards the front of the stove (maybe 3"). I seem to remember that to burn coal this plate is all the way to the back so the smoke goes up over the top of the plate and then to the back and up the chimney. If I am burning wood, I slide the plate to the front so the smoke goes directly to the rear of the firebox and then up the chimney. Is this correct? Does it really matter? Thanks for your help.