Every new version of dwm brings some changes to ``config.h''. These changes are shown in config.arg.h file of the package.
Thus file is extracted from tarball only during the emerge process, but it is handy to know, what are the changes, before actual installation. Still the tarball may be unpacked manually, but still it's handier to have ebuild downloaded the config.arg.h manualy. May be it would be a good idea to show the diff between current config.arg.h and the config.h of version installed during the initial phase of emerge process.
Not possible, would cause digest overlaps.
Not actually. The config.arg.h files could be stored in distfiles as config.arg.h-$VN.gz No overlap then.
No. We won't be manually mirroring such stuff, sorry.
Well, as You wish.