Yea I'm working with professional artist right now to see about making a pamphlet to include with the epoxy that talks about how to use it best for the various applications. What techniques work well, what doesn't, and why.
Biggest issue for sculpting purposes is that it likes to set up fast. The sculpting was more a secondary application for the epoxy as it was primarily designed to be used for pressing into silicone molds in thin sections, pressed into crevices between rocks to glue them together, and as a thin laminate over foam (like how we use silicone). Thin sections require a faster/stronger set time to make sure that the epoxy is capable of generating enough heat to make it cure within a reasonable time. The backdraw is that it makes sculpting a little more challenging as small batches are needed. So it's a bit of a trade off. I'm hoping that with the techniques my artist friend comes up with and the things you guys all come up with, we'll be able to have a good set of resources to help newbies with this advanced technique.
One thing you can try is to put it into the fridge, not freezer, and see if that helps. Just don't let anybody confuse it for food. The lower starting temp might help give a longer workable sculpting time.