Right now, mod_ssl picks up optional functions from mod_md in order to get
certificates and answer TLS SNI challenges. This would allow other TLS modules
to integrate themselves with mod_md also.
The alternative is to let mod_ssl offer more optional hooks which mod_md then
adds its callbacks to. That would allow for other credentials providers than
mod_md, but then integration with other TLS modules would suffer (I remember
someone was asking here about that).
I am tempted to leave the dependency as is, but am not sure what people can
make more with. Opinions welcome!