If the TP-Link requires some firmware to work let me know (it will be reported in dmesg as a failure to load something) and I'll add the firnware to the image. If it requires an out-of-tree driver, sorry but I don't have time or interest to chase down patches for realtek drivers that break with every kernel bump so all of them are disabled (and no current plans to change that).
Restart and shutdown now wait for Kodi to gracefully shutdown instead of killing the process after 5 seconds if it hasn't existed (it never does). This avoids frequently reported issues with Kodi trashing configs which are saved at shutdown, but does drag out the shutdown process compared to older LE releases. It's known and is a general Kodi problem not anything specific to Amlogic or these images. There is a long-term plan to refactor/rework some bit of Kodi which should improve timings .. but don't hold breath.
Hardware decode is still only partially working. H264/VP9 are now reworked and merged for Linux 5.7 and HEVC (not hardware supported on C2) will be next, but ffmpeg stateful API support and the Kodi side still need reworking. Most of the effort on that is currently focussed around Raspberry Pi but since Amlogic shares the same code paths that's not a bad thing.
No ideas about CEC as I don't use it. I do have a patch in the codebase to disable dmesg log-spamming when CEC is not supported (as I disable it in my AVR) but this is only //commenting out the message and it doesn't/shouldn't prevent actual functionality. Check Kodi settings?