@Megas
In my last game I didn't have any Pather interest (or at least I don't remember having any problems with them) despite having heavy industries with a Nanoforge and fuel production with a Synchrotron. My hostility though isn't quite at 100% (89%), maybe that is the reason for that? I've also never had Free Port on at any of my colonies. It's kind of nice not being bothered by the Ludic Path, though there still is a decent amount of pirate raids and expeditions.
Which release did you play? As soon as I updated to RC14, at least three more core worlds (Sindria, Aztlan, and one other) that did not have cells previously suddenly got them.
Also, if your colony was size 3, then cells never appear until size grows to 4. (If I plan to then spam spam Alpha colonies, I plan to keep all of those colonies at size 3.)
Like I wrote before, as soon as I installed items into Ground Defenses and Patrol HQ, my colony got a Pather cell because both items added +4 interest each. Nanoforge and Synchrotron still add +4 interest, so I know I will get a cell if I put those two together on a colony bigger than size 3.
Re: Impact MitigationThe main reason to take it now is less damage to weapons and engines. If not for that, I would take Ranged Specialization because 800 range is not very long. Even Harbinger can strike at about 1000 range with Q. Disruptor (enhanced by Systems Expertise) and Phase Lances with range extensions, and getting max range is not hard with a capital. I wonder if Mine Strike counts for Ranged Specialization.
Impact Mitigation lost too much protection. Now I am considering dropping my frigates and chain deploy solo phase ships (Harbinger or Doom) to take out their small ships across multiple rounds until only the big ships are left, then deploy my fleet against their weakened fleet.