I'm fully aware the game is in alpha and a new renderer is coming soon.
That aside, we are constantly dealing with poor fps in cities even with great computer. I often get more than 100fps in forests with everything at max setting but less than 20 in cities, so I often change the quality object to low when I enter those area to get playable framerate (I don't touch terrain setting since it's server side).
What I'm proposing is an option to set some settings to Auto based on the fps drop :
If you are beyond a certain fps (witch we can set), game increases object quality without you doing it.
If you are below the lower frame limit, game reduces object detail until your fps goes higher than this limit.