I've used Projectivy for years on every Google TV stick I own (Google/Onn). Works perfectly with full customization/zero ads on the free version and has a workaround to take over the Home navigation to bypass the built-in launcher without ADB or rooting. I chip in for the premium version to help out the dev since I get so much value out of it but the freemium features are mostly just cosmetic and the free version has everything you need.

Projectivy seems good and I use it on cheap android / Google TV devices since learning about it last month.

I tried projectivity launcher on one of these and it seemed reasonably good.

ADB is rarely actually a requirement unless you really want to do it the "right" way and fully remove the launcher.

I always use a custom launcher (Projectivy) on my Google TV devices, lately typically the $20 Onn stick and intercept the Home navigation to open the launcher either using the option built into Projectivy or with a free app from the Play Store/Fdroid.

Takes <5 minutes to setup everything once and then I basically forget the native Google TV launcher exists. Pretty much unbeatable value for a $20 ad-free Jellyfin/Plex/Kodi/Stremio setup. YMMV with different models but I also had no issues remapping the remote buttons from Netflix/etc to my own apps (including the "Free TV" button to launch Stremio which I always enjoy).

Also (somewhat ironically) the best smart TV OS to look for on cheap/subsidized TVs is built-in Google TV. Since they can easily be configured as 100% "dumb" on startup without any ads/nags/etc (it's the first question you're asked). The TV never hits Wifi to update and the remote/menus just do normal TV stuff without any "smart" features. Otherwise, it's luck of the draw how miserable/impossible the manufacturer makes avoiding Wifi/updates.

(Or you could do the same process installing the custom launcher on the TV's built-in Googe TV, but then you're at the mercy of the CPU/RAM the OEM included in BoM some # of years ago and lose the clean seperation between dumb TV/replaceable stick).

$20 Onn stick + $199 "smart" Google TV in dumb mode goes really far these days for a locally hosted setup without ads/annoyances.