If terrain synth is too heavy on the FPS maybe you can add a transition strip East and North with some mountains like BIS has done in Zargabad. That could hide the map limits.
Now that I gave some time to play this map I must say I love it. It's really fun to play and provides very interesting combat situations: the roughness of the terrain makes it unpredictable. Enemies can be all around you hiding behind those bumps. And when stupid AI stands in the open (like they always do) it's less noticeable, so it also makes combat a bit more realistic. The chaotic road network makes the map more difficult to commit to memory which provides better replayability. Also love some details like the amount of ponds (a river would be nice but AI can't cross it so it's better not) and the leaning power poles which seemed odd at first but are actually more realistic this way. Very nice detail: trees of the same class are placed with different heights which make them look more varied than they actually are. I'm also very happy with the choice for palms (I've tried another variety here but it's only a simple object so not a good option in this case).
I like the map just as it is but here are some suggestions nonetheless:
-The roughness is one of its strong points but sometimes in the green region it seems a bit too much. There could be just a few flat areas here and there that would break the continuous undulating roughness. As a bonus that would also make 3den base building easier.
-More variety of walls in particular in the more densely populated places. The mosque walls that are used for the villa suit it fine but are way too extravagant for the more simple houses. You can use vanilla walls for that like Lythium does.
-Increase variety by using more vanilla assets that are compatible with the setting. These for example: "Land_Unfinished_Building_01_F", "Land_Unfinished_Building_02_F", "Land_i_Garage_V1_F", "Land_cargo_addon02_V2_F", "Land_Slum_House01_F", "Land_i_House_Small_03_V1_F"
-Add some dry grass or little stones in those completely empty bumps that look too clean in the green region.
-Improve the industrial areas and make one or two of them bigger.
-IMO the huge mosque in the middle of nowhere doesn't make much sense: why would someone build it there? who would go there? I think a cement or mining facility would better suit the place.
-I would love to see some powerlines in those poles (I'm not serious I know that is very difficult to do). But you could add just a few poles with lines of the bigger kind.
-About the vegetation: cultivated bushes and trees tend to follow straight lines in the real world. Random bushes and trees usually only exist in wild unpopulated regions or on the edges of properties or edges of roads.
-Big water towers should be only exist near populated areas.
-Satellite antennas on some houses: "Satelit", "Land_SatelliteAntenna_01_F"