For my needs it is perfect, generic enough. But what do you mean by improve?
Well, this could be very long to explain. The Renoise automation editor, as a concept, is one of the most powerful things that this DAW can have. Notice that it is capable of controlling each of the parameters of each of the chains of effects. This, seen in perspective, is very beast, it is magnificent.
However, the user does not have a graphical representation of comparison between parameters. Adding curves is too complicated (you have to make many dots, a lot of unnecessary information). Doing work among multiple patterns is a complicated task. It also does not have generic curves. It does not have a tool that limits a specific range so that it generates a specific curve by pressing a button. This can be done with a tool through LUA. But it is a floating window to control the automation editor, it is not something integrated. In the end, managing the Automation Editor is complicated. It is not a very worked area.
I like to compare the automation editor with the sample editor. The sample editor is quite worked, with many hours spent on it. The automation editor still looks like a beta. It is possible to improve and add many interesting things. And the excuse is not build yourself a tool. The problem is that this tool is not integrated, and this adds more difficulty to its control.
It all has to do with speed. A user should not go as a bullet while entering notes in the pattern editor, and then take a break with the automation editor, because it does not offer the necessary tools to go like a bullet. And it gives a little bit of anger because the automation editor can control all the parameters of each effect of the chain of each track. This is very good, but very little exploited.