That’s a great write-up. I use Kodi for my Blu-ray collection as Plex is a bit overkill for my use.
A couple of suggestions I’d make:
If you have a spare computer to encode on, or a fast CPU and don’t mind tying up your computer for hours on end - encode using the 265 Codec. It produces much smaller file sizes at the same visual quality. Useful if HDD space is precious e.g. on a compact HTPC.
I’d also really recommend playing with the Denoise Filter.
Do lots of small encode tests and compare the results in VLC before you encode the whole move/series.
In particular I like to use the NLMeans filter with the [Light/Medium] Preset and the [Film] Tune. I find this massively reduces file size and is barely noticeable when done using the [Light] Preset.
You can test this by picking a noise and grainy source (such as Battlestar Galactica 2003) and encoding a short chapter using NLMeans and comparing it with the various presets.