Unfortunately the Smart TV hacking community is not that active.

It is a bit more active than your links seem to indicate, but is not very well organized or easy to find.

Use https://cani.rootmy.tv/ to check recent status of rooting LG TVs models. Many slightly older, 2+ years old TVs are still rootable, due to this exploit from 2024: https://github.com/throwaway96/dejavuln-autoroot

Had to look up what a few of these were myself, check the sidebar resources: https://github.com/awesome-selfhosted/awesome-selfhosted