Iv actually just used the recommended bake instructions on the clay, iv even done this with a G1 pony, I do keep a close eye on them though. SO far haven't had any melty disasters, and i do this quite a bit.
Skeen is right about the G3 magnets! however I usually just keep them in, (because I forget xD) and once the pony is cooled off, the magnet will usually just fall right out (or stay stuck to the pan because it's a magnet rofl) I usually glue them back in because I dont like the hole they leave behind.