This two images differ only in the wifi interface and the remote control configuration, so it will work for sure without any boot problem.
And this will definitely solve your wifi problem as well. All you have to do is set up the remote control via SSH:
Codecd /storage/.config/ wget https://github.com/dtechsrv/LibreELEC-AML/raw/master/projects/S8X2/devices/MXIII-Plus/filesystem/etc/amremote/remote.conf reboot
But of course by answering your question: Yes, you can restore safely to the original MXIII-G image.
I just install the LibreELEC-n200-AP6330_2G.arm-9.2.8.3 to my mxiii-g tv box. Everything is seems working fine. I also set up the remote control. Thank you!