Map design. Alot of maps in BF4 I don’t touch due to terrible design. More infantry-focussed maps. Better contrast between characters and the environment, make it harder for enemies to stand still in one spot without being easily seen.
If you’re going to have linear maps like Locker or Metro add a few more pathways to reduce the bottlenecks.
Give server owners the option to make some changes without having their servers become ‘Ranked’.