Yesterday the Gateway 3DS team posted an update on their homepage. They are stating that all 3DS firmwares up to 9.2 (included) will be supported, and that the update will be published soon
Firmware release update
Posted on December 18, 2014
We know many Gateway users are eagerly anticipating our upcoming native firmware support for Systems over 4.5 up to 9.2.
We have currently implemented support for firmware versions 7.0 until 9.2 and adding support for lower versions every day.
We apologize for the delay but want to reassure our users that it will be released soon.
Our proven policy is not to rush a product for a quick shameless buck, but to release highly featured updates which are also future proof. All Gateway owners have been enjoying our product for up to 18 months now and none of them regret their purchase. The same will remain for new users who we are sure will enjoy their Gateway, probably for the lifetime of their console.
Thank you for your support and we ask you for just a little more patience, our release is now just around the corner.