I do not entirely approve the above proposal. While I don't know that much about other ores, I've checked the Tau ones, and based on your minimum 2-3 system route criteria the only problematic destination I found in all three cases is Kagoshima in Kyushu, one jump from both T23 ores as well as Raw Hydros. Second closest to Niobium and Beryllium however is Valence in Dauphine, the removal of which would exclude almost the entire Gallic Unlawful playerbase from ore business as they are not necessarily (and mostly aren't) alighend with Outcasts. (E.g. Council could team up with IMG to haul stuff to Valence when the royals aren't looking...) Besides, OA is already a destination for Tau ores. Overall I approve the idea of longer routes too, but to me it seems that in the case of those three ores it's mostly done well.
Perhaps others could comment on your idea in regards of ores in other regions too.