Not exactly what you want, but this tool helps me tidy up the fx lane view, keeping all devices minimized while maxing the selected device. Might be helpful for you?
This tool will automatically only maximize the currently selected DSP in renoise`s DSP lane while minimizing all others. This is to help to keep the DSP lane tidy and keep the currently selected DSP open for editing.
To enable simply right click on a DSP in renoise and choose the option “Auto Maximize Selected Device” from the menu.