I have a Regency I2500 Insert. It takes 16" logs N/S and 18" E/W. Before I got the Insert, A lot of my wood was cut to 18". I have some Pine and slightly punky Ash this length that I am burning now. Consequently, those pieces have to go in E/W. I am noticing that towards the end of my burns that I have effectively chunks of Charcoal towards the back. I am attributing this to the East West pieces limiting the Air that gets to the back by acting as a wall. I don't necessarily see this as a problem , but should I be doing something different? I am thinking maybe alternating with 16" NS pieces on the bottom with 18" E/W pieces on top of those.