Sketch - Upload features CRS Requirement

[chughes-lincoln]

For uploading features for a sketch from a file, is the file required to be in 4326?
When I try to upload a GeoJSON with my local CRS or 3857, I get an
error saying there were invalid features found. If I reproject the data
to 4326, the file uploads successfully.

If there is a CRS requirement it would probably be helpful to add that information
to the Upload Features dialog.

[klassenjs]

GeoJSON (and KML) is always EPSG:4326 [1,2]. I'm +1 on adding that as a note to the docs.

[1] https://datatracker.ietf.org/doc/html/rfc7946#section-4
[2] https://gdal.org/drivers/vector/kml.html#kml-keyhole-markup-language

Rant:

No, I don't agree with the committee decision to punt just because CRSes are hard. CRS transformation is not a lossless operation. Aside from rounding errors, it also often breaks topology, and changes the ground path that lines and curves follow between the points/vertices. To fix this either requires knowing the exact transformation steps so it can be exactly reversed, or introducing new vertices to limit the error to an acceptable level. Neither of these options are very appealing. This means that GeoJSON is fundamentally not usable in a standard compliant way in situations where the source data is not already in EPSG:4326 and the accuracy of the data matters.

Yes, I do use GeoJSON with "invalid" CRSes between my internal endpoints to avoid the above issue, but that doesn't really work for things with a public endpoint.