It would be great if we could group app indicators together to preserve space on the taskbar, similarly how it's done in Windows. Also, adding an option to change padding of apps pinned on taskbar would be great (this can already be done in Dash to Panel, but I prefer using Zorin Taskbar).
This is how my taskbar looks right now:
I like to pin many apps (maybe there are others who can relate 
), and as you can see there isn't much free space left.
Grouped app indicators mockups:
