In subversion versions 71-74, the code has been converted to use Django templates for nearly all configuration served up by wikipbx, "nearly call" because the dialplan xml does not use templates .. and I'm not sure if it really needs to. Sofia, xml cdr, event socket, and directory configuration are now all template based.
Now it should be much easier to customize the configuration to your specific needs when that customization is not supported in the web interface / database.
The templates are still outdated compared to the current config, and will be brought up to date soon. But it should be fairly easy since it is just a matter of merging in new parameters to the xml template. (all templates are located in the freeswitchxml subdirectory).
WARNING: don't try to use default variables like $${foo} that are defined in vars.xml in the static freeswitch config. This will be passed verbatim to freeswitch, which will not resolve the variable. Not sure if this is a bug in freeswitch or by design. Only tested against an old version of freeswitch (10300) so your mileage may vary.