[Geojson] "coordSys" member extension?

[Lorand Kedves <[e-mail]>]

Dear GeoJSON Board,


We created a management interface to a system with ~1GB of data, using
GeoJSON to server-client interaction and integration I/O was very
convenient and we could rely on sophisticated tools. (Thank you!)

However, the system used a different native coordinate system. Converting
all data to WGS84 and back all the time was not feasible (displaying and
saving data should be done in the system native coordinate system). We
decided to still use GeoJSON as a transfer format, although the actual
values were invalid. At the UI, the display component required this
conversion to get valid GeoJSON. I added a "coordSys" member to the GeoJSON
Object, set it to the native id on the server and used a stock tool to
in-place convert the received coordinates data on load.

I think this optional extension is useful: allows systems to use their
coordinate systems, they are responsible for the conversion but still can
produce valid GeoJSON. I am quite sure you had already considered and
rejected this idea. What was the problem with it?

Thank you
  Lorand Kedves