What is a standard benchmark for memory usage on IOS? And more

Hello developers! These are quite a bit of questions here, but any help or insight would be deeply appreciated. We’re developing a game with many uniquely modeled & animated actors (with LODs) on the IOS platform. Our memory usage ranges from 140mb to 200mb. Our target hardware has 512mb or ram, so that’s a bit under 40% usage. Which leads to the question: what are the some benchmarks for memory usage? Are we on the higher end of spectrum of memory usage or are we on track? Also, does unreal cache all referenced assets on start? If so, how do we go about trying to manually set up our caches?