TL;DRRemove the performance hit for radar "near" visibility.
What ?Right now radars repeatedly "scan" nearby chunks, which has a notable performance impact once your area of visibility grows, especially since radars can overlap a lot if you dont manually place them.
So instead of the nearby scan routine, just mark each chunk as visible permanently as soon as a radar has been placed within its range and has power with a reference on each chunk to what radars cover this chunk.
If a radar has been destroyed the entry is removed and the chunk will dissapear unless there are other radars in that list.
If a radar lacks power, it doesnt reveal anything or you can scan its sectors with a cooldown similar to now, and once power has been restored mark it as permanent again.
Why ?It removes the performance impact of having the map revealed.
This would also be very beneficial for allowing research that increases radar ranges (right now those cost a lot of performance ) or simply ignore the penality of overlapping radars (or entities with radar properties) without having to worry about the performance impact.