Sorry, I was under the wrong impression that this was about the tile/btg naming scheme in use, i.e. converting KSFO/KLSV to the matching set of tiles to be included.
As far as I remember, the corresponding code is part of SimGear, and some of it is exposed to scripting space - so it would be relatively easy to provide an integrate GUI dialog to convert an ICAO identifier into a set of file names, or use that to query the navdb cache and procedurally create a matching set of presets to be used.
I don't remember the specifics, but I think we were contemplating to rename and split up/partition preferences.xml anyway - so that it would become much more straightforward to use a separate/external file containing such presets, which could also be dynamically patched/re-created.
Admittedly, I was considering to provide a corresponding Nasal-based solution (because Nasal happens to have bindings for the corresponding APIs/subsystems, like the navdb) - however, feel free to post a link to a corresponding presets.xml file so that people can take a look - obviously, for a standalone solution that may run as part of the release process (i.e. on the build server), a Python based solution would seem to make much more sense.
PS: Thanks for detailing/documening the process - until we have a better process in place, it might make sense to add this write-up to each nomination thread, and require submissions to be complete, in the sense that they need to contain the required data to be considered - which should also help filter future nominations.