First of all, the charts use OpenGL, and according to Apple’s OpenGL docs the simulator should not be used for profiling of OpenGL apps, so I think the 23MB is a bit of a red herring and probably caused by the OpenGL simulation.
If you use the default theme for your charts then it uses a static theme, to avoid recreating it for multiple charts. I’ve logged an issue for us to investigate whether this is the best approach. In the meantime you could create your own theme and pass it to the chart on initialization, which will avoid creating the default theme. However, my tests in Instruments suggest the memory saved is only in the region of 30kB, so not the sorts of numbers that would cause an out of memory exception.
Using a single chart at a time and around 1000 data points should not be causing any memory issues. Have you profiled your app using Instruments to determine what’s causing such high memory usage? If it is caused by shinobicharts then please could you send us your profile so we can take a look?