Reducing size of dSYM files for symbolication

We are looking for ways to reduce the size of dSYM files from Apple platforms. We need dSYM files just for symbolicating stack traces of crashes and in Crashlytics blog I read this:

These mappings actually hold much more than needed just for symbolication, presenting some opportunities for optimization. They have everything required for a generalized symbolic debugger to step through and inspect your program, which may be a huge amount of information. On iOS, we have seen dSYMs greater than 1GB in size! This is a real opportunity for optimization, and we take advantage of this in two ways. First, we extract just the mapping info we need into a lightweight, platform-agnostic format. This results in a typical space-saving of 20x when compared to an iOS dSYM.

Reducing size by 20x sounds very good but I found little information on how this can be done. Do I need to learn details of Mach-O DWARF to achieve this or some of the command line tools can do this? I also wonder if the stripped version can be used direcly afterwards for symbolicating.

Thanks.