So, under the hood, this item actually is a roboport. It's just that it doesn't have its own logistics or construction range and can not itself house robots or repair packs. If I were to increase the range of the logistics area, it would connect just like any other roboport where its logistics area must touch or overlap an existing one.
In balancing the mod, I felt the added benefit of 10 charging spots was worth forfeiting any ability to hold robots, repair packs, or extend your roboport area. I also use this mod myself at the very edges of existing logistics areas (often to chests that are on the outer edge of the logistics area). Giving Robocharger a logistics area would limit how close to that edge I can place them.
I could consider having a second option with a logistics area.
