I'm not in knowledge of developing or engines but i noticed that actions that increasing or decreasing some number (building/destroying/capturing/repairing, gathering resources, hitpoint decrease due attack/increase due healing) counted by engine at immediate time and right at these times fps are decreased. However in other similar games all actions that changing these numbers counted at a certain time like between a second or two. I think this must be tried to see result.
Also there is something wrong with the unit movements in formations and routes that causes fps decrease as everyone c