Thanks Geoff! I did model it over on anydice.com, but that hurt quite a lot too! The combination of 2+ zeroes resulting in an outcome of zero, with only one face of duplicated numbers being exploding, just blew my mind (though it's part of why I backed the KS - I'm a sucker for mechanisms that I find interesting)
OK! I just posted a new update which includes a new node called EXPLODE DICE BY SIDE. You can choose one or more die faces to explode on, rather than values. Just type the side numbers into the box, separated by a comma. For example, if you want to explode on sides 5 and 6, enter "5, 6".
This will also take symbol dice, and explode those based on the side.