>>1974322>At what given resolution would it be worth reducing the bitrate
Depends on what you mean by that.
I personally never use a fixed bitrate for my webm's but always use CRF to get quick and decent looking results on my stuff at a given resolution.
It also makes maxing out the filesize VERY easy I think.
Like i tend to stick with something around CRF 20-40, 50 for VERY bad cases combined with a low resolution.
Usually I try to keep my stuff around 360p at the least and go higher if the video allows it.
It's all about testing around and finding the best method for yourself really.