the Wider 10m option does not scale to 10 when using GPS in game option automatically and still uses the original setting for manure spreading.
Viewing post in John Deere 34 Manure Spreader FS25 comments
You would need to add an ai areaMarker tag to the 2nd spray type in the xml, create that new ai area in the i3d. Look at the Bredal k105 xml, sprayer section for reference. Also seems to be a game limitation where when you change to the wider width on the fly, you need to detach then reattach the spreader before ai will read the new work area.