A small galaxy is roughly 500+ LY from north to south. 150 LYs is a good portion of the galaxy. Not being able to build any colonies within 150 LY of an enemy orbital fort is a HUGE disadvantage.

Warp 13 packets travel 169 LY a turn if i have the calculations right.
...
And due to order of events, you actually need 169*2 LY distance to be able to intercept a packet with freighters.

because your fleet can be intercepted and killed, and slowed with minefields, but packets cant.

You mean the starbases that they just keep re-building?

are you really going to try and intercept every 1 man colony fleet that the AI spams? We are talking about dozens of 1 man colony fleets here.

I'm confused, how are you using gates to attack? The only thing you can do is try to warp them to your nearest planet and then travel through normalspace to the enemy planet, but if you are doing that there is no reason to not have your logistic ships start from the nearest planet.

minefields dont overlap properly and the center is often not where the minelayers are...

You dont even need mine sweepers, which is my point. Regular beams work just fine in clearing minefields far faster than the equivalent number of resources can lay mines.