Question:
I had a guy do 900 acres survey and sent it to me. When I eventually write the design off to *.gps for Field Level what considerations on such a large field do I need to be aware because I know there is some kind of limit?

Answer:
Best to cut that large survey down to individual fields using Tools > Existing Topography > Polygon Delete.
gps file limit is the exported boundary zone area must fit inside approximately 500 x 500 grid. So at 5m export grid spacing that would be 2500m by 2500m.