I've let 415 cool in a presto pot and it look butt ugly, so the difference must be the USA. Since you did not "pour" the presto pot at the slushy stage and it looks good, then why should adding it ti containers at a non-slushy stage matter? One difference might be rate of cooling, it takes hours for a full presto pot of 415 to harden completely. The other question is why does pouring at the slushy stage work? The wax is starting to harden and then we pour it, kind of seems like a bad thing if we want smooth tops but it works. Could mixing or stirring substitute for pour slushy? Pour into the container at a warmer (non-slushy) temp and stir slightly as the wax becomes cloudy. I wonder if this would work. Maybe the bad tops of 415 are due to uneven cooling, pouring at the slushy stage or stir should fix that.