When trellising a bar chart, it would really useful to be able to remove/filter out categories that are zero in other trellis panels, to avoid cluttering sparse trellises with all the categories in use. This issue can be painfully viewed in the attached image where I have created an example.
I agree, but I don't think I have any power to merge or delete the idea after once I found the previous idea.
Sounds like SPF-I-2740 ("Multiple x-axis scales in trellis")?