Green Guard :
1/4 NM OFF Track setting should be used EVERYWHERE...
Lateral offset has been discussed here before extensively in tech log, and in ICAO . IFALPA ATS past chairman went on a personal crusade with it but lost. because numbers show that with offset you mathematically increase the collision risk. (check ICAO doc if you want the details and the formulaes)
Even for 1 NM you'll never get any remark from any ATC all the way down to APP
Wrong in RNP 5 and RNP 1 airspace, ( most of Europe dense continental, and I suspect parts of the US as well)
Offset make sense in areas with no surveillance ( parts of Africa, Oceanic, remote desertic, polar , etc..) but definitively not Everywhere.
For info the part of the Amazon where the collison occurred was declared a radar controlled airspace by the Brazilian airforce. The final reports says otherwise.