ASK NC

After watching your videos I have gone ahead an purchased a TS-464.

I am planning to use it as a plex media server.

I would stream to 2-3 mobile devices, 2-3 tvs and will utilise a HD home run Quad tv tuner .

Current streams mostly 1080p but would like to future proof to 4k if possible.

Which hardware upgrades would you suggest to maximise its plex media server ability?

You can use 64 series for local 4k streaming. Remotely you can do it using Video station app.
Nothing else to invest in this box.
If you need plex 4k remotely, consider this https://www.youtube.com/watch?v=j4Z-Aojo3JI

I hope this helps.