I would not even think about selling pies yet as a lot of testing needs to go into these for the issues you described (tunneling and spilling over). I make pies as well and been working at it for a while now using 50/50 pillar/votive wax. I will say the flatter the tops of the pie (for me) the better the burn. I'm able to get a full mp, minus the crust, initially. The more it works it's way down the tin (google 5" tins and you should find plenty suppliers available) the crust will start to melt gradually. I've been successful with 3, eco 2s in mine as long as my pie is realitively flat on top. If you do sell them they need to be on a plate/hot pad too. Tin gets very hot and could burn the counter top they're on.