UpSet plot queries?

[marwa38]

Hi awesome people
I have some queries if you don't mind commenting on, much appreciated.
1- I wonder if you noticed some differences in results between using Venn diagrams and UpSet plots? the number of items in the set size appears to have 1 item higher than list I have for each column. I presume that the title of each column is included in that? Here are the codes:
upset(fromList(data_filtered), order.by = "freq", nsets = 38, nintersects = NA, text.scale = 1.8,
set_size.show = T, set_size.numbers_size = 6)
2- I can't find away to show the bottom set size, it usually not shown, and if I reduced the size to appear, the other items in the set size part become quite small, any advice?
3- If I choose a specific number of nsets, the intersections will show according to the highest number?
The screenshot below as an example: