Dynamic Frameworks and App Launch Times
Peter Steinberger links to this discussion started by Eloy Durán. This gist of it is that dynamic linking can really slow down launches, especially before the cache is filled.
Beyond that, there is nothing more I can do for you at this time to make framework loading go faster. You can follow up on your bug report on bugreport.apple.com if you wish to know its status.
An app I’m working on has no more than 10 frameworks, and I’m also seeing >3s launch time slow-downs caused by this, and I hoped that the DTS would result in some workaround.
So it seems that static linkage is going to be the only pragmatic solution for the foreseeable future (dyld optimisations, if any, would probably take a while to make its way to us) and has been proven to work/allowed.
Due to having no guaranteed stable ABI, it seems extremely unwise to even think of using static libraries for swift.
Perviously: iOS Needs Frameworks.