sorry to burst you're bubble but according to the radar range of the strats {i marked them with neon green},you can not get within a sector and a half of the HQ without warning,even if you go off map it still shows a red arrow that gives you away. so it all boils down to people not caring
You don't need to go off the map.
If you keep on map, but south of the troop factory, the factory will NOT flash. Been there done that. That's why I included an actual picture of that route. I'm on map and the factory never flashed. Only the HQ did when I got in range. 3 Minutes later I'm over it.
It's impossible for any kind of interceptor to be there in time.But even if an unfortunate NOE raider would make the factory flash, he's still safe. Nobody knows where he's at, and nobody knows he's actually ib HQ. You still would have someone to race to the HQ immediately 'just in case'. But a conventional fighter will again not be there in time while a Komet pilot has not the fuel to loiter.
Now take into account the probability that there's actually a player sitting in the tower and ready to take off immediately for this. Particularly with the low player numbers these days. And how likely is it that you will find players that "care enough" to patrol the HQ area for hours?
Are you expecting players to keep on non-combat duties, either patrolling or resupping an HQ for hours?
Again, it's all a matter of balance. One palyer, with very little risk, can screw up all dar for a country for hours with little to no chance to stop him in time. On the other hand, it may take a very high effort for the hit country to bring dar back up. Which is, due to low overall numbers (less than 20 players on a team total!) often not even possible.