I’m not aware of any method for Terminal to estimate render times.
The Terminal render method I’m familiar with invokes the After Effects Render Engine but without a front end GUI which is what one sees in AE.
Perhaps some clever scripter could write a hook that polls the Render Engine for an estimated render time.
I’ve found those times wildly inaccurate since AE seems to guess based on the time it takes to render the current frame and assumes that all future frames will take as long.
An alternative is to use Adobe Media Encoder to render, which still allows you to work in AE while AME renders in the background.
Of course YMMV depending on the nature of the render and the hardware specs.