I am guessing the dont reserve space at border panel preference is only suppose to move the desktop icons inwards so they are not below the panel. But it seems like i can have multiple arrangements of the desktop icons which is funny but maybe not intentional. With two unlocked panels i have them at the sides and then i see 3 icons in a row on the desktop. I can then move the icons around and place then a random place. But then if i move one of the panels away from the border instead of all the icons are just moved outwards the hole arrangement is switched. So now i have the 3 icon again in a row and i can place them some random places. Then if i move the panel back to the border (to trigger the reservation of space) the icon arrangement switched back to how the icons was placed before. And with the other panel i can move that away from the border to to get yet another icon arrangement state. So its sort of like having multiple workspaces but instead of remembering the placement of the windows it remembers the placement of the desktop icons. Im guessing this in not intensional.
This is not how you write a bug report. I am not sure if I understood it correctly, but icon positions are saved per "work area" and are restored accordingly. ~/.config/xfce4/desktop/icons.*.rc
So when the desktop is a certain width/height because of area the panels take up then each size can have totally different layout of the icons. So if the panel is 100 pixels wide and i want it to be 110 pixel wide then the icons can change place just because i wanted to change the size of the panel. That seems odd because why should changing the panel size affect the icons placement other then the 10 pixels extra width?
Adjusting the panel size changes the work area. However, this is only the case when the setting "Don't reserve space on borders" is enabled.
Correction: when the setting "Don't reserve space on borders" is disabled. It is my understanding that the current behavior is the intended one.
If you change screen resolution the icons can still jump around regardless of "Don't reserve space on borders". So the Home folder might be at the top left at 800x600 but then you change to 1024x768 and now its in the bottom right corner. I managed to get the desktop icons below the panel (hidden) even when space is reserved depending on what row height,number of rows i select.... To me reserve space sounds like the icons should not be allowed below the panel. I can see the desktop icons through the panel if i make it semi transparent. And then how do you get the icon away from below the panel? Guess you can unlock the panel, move the panel, move the icons, move the panel back and lock it. And then you have to do that for each work space size. I guess i can create a new bug for that for not allowing icons below panels when "Don't reserve space on borders" is disabled.