dropping wifi support
I don't remember having relevant driver present at any time.
It looks like 9.2.6 still supports OPi Lite.
This version has plenty of problems, that's why it was never released as stable for Allwinner. Also no fixes were backported to this version.
Can I find out which Wi-Fi chips are supported?
I don't think there is a list of supported wifi drivers. In short, all USB wifi dongles (and few SDIO) which are supported in mainline kernel should work. LE adds few more wifi drivers - LibreELEC.tv/packages/linux-drivers at master · LibreELEC/LibreELEC.tv · GitHub (RTL8*). List of commercial dongle names would be far too long to list.