Not sure if this was mentioned already, but the cheapest trick to get rid of the "puffy space rocket" problem is to use the Distance and
Distance Variation Parameters inside the PStorm Node. With a high velocity value no one will see if the particles are emitted
exactly from the Emitters position or a little bit in front of it.
I created a little xpresso script for subframe emission using thinking particles and custom data channels , i'll send it to you this weekend Of course this is still a linear calculation, the real solution would be to convert the previous positions to spline points, subdivide them, and get the point values from the subdivisions. Sounds like a complicated python script :S