I can't recommend the Google TV/Chromecast if you have to interact with multiple apps or plan on using the Discover screen or search. The remote is finicky and feels cheap and the device itself is totally underpowered for Google TV. Its Amlogic SoC is slow as fuck and often drops frames and the 2GB of memory are barely enough to keep the bloated interface in memory while the storage is often full even after just installing a few apps. It has gotten a bit better after even Google had to admit that performance was abysmal but the optimizations just fixed the most obvious shortcomings.

I have sinced unsubscribed from all streaming services and just rely on the put.io app on Google TV to handle my media consumption needs and it is good enough for that. So if you just need the Stremio app (which I haven't used myself) to access local content, you should be fine. I never saw it struggle with 4k HDR content nor did I encounter A/V sync issues.