Reduce memory usage on startup: more mmap, or better sqlite tuning
Proposal
iOS has this RAM usage limit of 50 MB. memory-mapped files are not accounted against that limit.
See this Quora thread for some details about the Jetsam component of iOS, which does this.
The general memory consumption of Arti with Onionmasq I'm currently trying to get to run on macOS and iOS is somewhat ok, but esp. starting up with a warm cache overreaches that limit.
See this memory graph made with macOS (which doesn't have that limit):
So, to get Arti / Onionmasq available for Orbot (and Onion Browser, which relies on it!), all files should be (at least optionally) get mmapped, instead of opened and slurped into malloc'd memory.