Since the product is now released and into Nintendo’s hands by now, anything above 6.2.0 will most likely never be compatible.
We can’t repeat it enough, do NOT update if you want to be able to enjoy the only solution for your 3DS: Gateway! You have been warned!
In any case: NEVER update, as Gateway never know if they can make a fix for any update. Remove automatic updates by enabling parental control to prevent any accident.
Currently it is not compatible with firmware above 4.5 ,but Gateway is working on making it compatible as quickly as possible with 5.x and 6.x firmwares. It is most likely to happen in the weeks to come since Gateway is done with V1.0 of there product and can now fully concentrate on newer firmware and new functions.
Below are links to .zip which includes V1.0 manuals and files for Gateway 3DS.