For my part, I'll just restate what I've said. Col 70 is effectively a huge bubble/sphere (approx 1,000 ly in diameter) however, there are large bubbles within it which are not permit locked. These are not Col 70 sector systems. These include Witchead, Trapezium, Spirograph, Orion Dark, an NGC group and various others. Horsehead Dark is in there but is locked.
When one of the unlocked bubbles is near the edge of the Col 70 bubble, the result is effectively a wall of locked Col 70 systems.
The wall is thin and easily jumpable or even fully breached in places allowing you into the various unlocked bubbles.
What I was not able to find was any unlocked systems completely within a Col 70 piece of space, i.e. where it is surrounded on all sides by permit locked Col 70 systems. I did find plenty of HIPs, etc. completely within Col 70 pieces of space, but all were locked.
Denali may have found some unlocked HIPs completely within Col 70 pieces of space however. Over to Denali for more info on that front.