So... since having low terrain without any grass is an option i'm pretty sure 99.9% of the players use it. Having no grass is fine, but low terrain details create players/NPCs/Vehicles that glitch into mountains or that float in the air at medium to longer distances.
Is there any chance of removing (or cutting) the grass while being able to keep terrain details on Ultra? Server Side that is.
I know there are some options revolving around this, mainly in the clutter class. I once played on a server that had the grass cut down really low so it didn't interfere with shooting when prone. That might still have been ArmA 2 OA though.
scaleMax = 1.0;
scaleMin = 0.5;
clutterDist = 100;
These three might be a good starting point for testing...