Performance with Dynamic Modules

I have a dynamic module that has 4 layers (Category, Sub Category, Sub Category Group, Product).
I am noticing that any custom code written against this isn't cached properly, is this left up to the developer to implement or is there some caching that can be enabled for fetching content out of dynamic modules?

Also, I found a sample somewhere that showed how to retrieve the live child nodes by getting a list of the master children and then pulling the live children where they had a parentid of the master. This seems to result in a ton of extra sql calls but I can't seem to find any better way to implement this. Any suggestions are greatly appreciated!

Thanks,
Ryan