Well, all of that was described in the link above. In my experience, KDE showed me that it made a separate .trash-userid folder on my second drive for each user when Xfce 4.12? didn't. Each desktop environment handles it in a unique way. The result is that I couldn't move items to the trash, only permanently delete them. When the folder became available the trash worked.
On the other hand, I had linked /user/downloads on my second disk. When I deleted huge files they stayed in the trash on that disk, but at some point this stopped being the case and it moved the files to the trash on first disk with the cost of transferring.
Great!