Aha understood now I get where the issue lies. Ok I'll drop the idea of using H.265. I have another solution for you! AV1
https://trac.ffmpeg.org/wiki/Encode/AV1
Thanks @themac, actually that is really obvious just renaming the file extension from .wz -> .zip then extracting...
I have taken the largest video "devastation" and I have found 2 important points just on bitrate.
* data bitrate overkill. Set at 2468 kbps, this can be better handled and dropped much lower.
* audio bitrate too high. Set at 499 kbps, for Stereo channel 128 bit is the highest required.
I did a quick test just dropping those values slightly and was able to reduce the file by 50% and both visuals and audio are completely fine. ( without changing anything else ) I can do all files, upload somewhere and you could even hand inspect them to be happy before replacing what is provided.