Actually, it is nice to ignore fighting when my main colony is at the easternmost fringe (-20% accessibility due to distance from core worlds). I would be so annoying to go from one side of the sector to another as soon as possible because I have a colony threat alert that I cannot ignore. So far, that fringe system has one great planet (+75% terran planet with decent resources), a secondary planet that is viable as a primary in its own right (+125% water world, with enough volatiles to supply fuel production at primary as long as sizes are equal and admin has Industrial Planning 2), and third that has high hazard (+200%), but has plenty of rare ore that the other two lack, and it is in the same system. Not sure if I sure build up that one or look for one for much less hazard far away from that system. (Tertiary is still at size 3 so I can abandon it later if I find a much better place.) I like to ignore fighting while I am busy looking for another system to colonize (that is closer to core) and more blueprints. Finally, the system has a fourth planet that is okay for colonization (+125% arid, but no resources aside from normal ore, which my +75% terran produces plenty of). I probably will leave #4 alone so I can colonize elsewhere. Two good planets almost on top of each other is nice for defense, although they still get through the orbital station sometimes.
Also, there is a 100% hazard tundra in the system next to that super fringe system, and I am think about colonizing that one to erect another heavy industry (to bloat my production per month for fast battleship building). I almost do not want to spend all of my colony slots at that one location (I like plopping down temporary waystations elsewhere).
I have up to seven colony slots from max colony skills, and I am hesitant to spend most of them at two good systems in one area at the eastern fringe.
There is also another +75% terran at the northwestern part of the fringe (but the system is not as good as the one at the east), but I will probably leave it because I do not want to go from one end of the sector to another defending everything from threats.