No, Gateway is not updated for 11.3 yet.
and
11.3.0-36 Breaks GW. GW currently DOES NOT support 11.3. You will either brick or lose A9LH. More than likely it seems you will just lose A9LH.
Again, if you attempt to boot GW Mode, while on 11.3, you will lose A9LH or brick.
If you want to use...