The Calcification and Duplication glyphs get a real workout in this one.
A Figure 8 pattern seems to keep everything moving over those glyphs, though making the last explosive feels slow since I have to wait for the last Firework to Duplicate before I can calcify the explosive. 
I suspect there's a way to suppress the inputs so you can make the final explosive while the last Firework is duplicating, but I couldn't get it to work in the minimum area-arms.