Sorry, but I won't add more coded options for the Lua side bar placement.
This said, as often for UI related things in the viewer, you may override the current Lua side bar panel definition so to change its layout and (in a limited way) placement.
Start with copying the skins/default/xui/en-us/panel_lua_sidebar.xml file present in the viewer installation directory into a ~/.secondlife/skins/default/xui/en-us/ directory (for Linux) or %AppData%\SecondLife\skins\default\xui\en-us\ folder (Windows), then edit that copy and change it as you wish (the changed file will be taken into account on next viewer restart).
E.g. to move the side bar buttons higher towards the upper right corner, you may simply make the panel taller. For a 1080-1200 pixels high viewer window, you could change
height="360" for
height="800", for example. Then (i.e. still with the panel height increased), if you want to move the buttons to the lower corner, change the first button's
bottom_delta="-30" offset for
bottom_delta="-600" or so. You may of course need to adjust these values for your needs (topmost or bottommost button position, viewer window height).
Just as well, you may reorder the buttons in the panel, so that, for example, they are added from top to bottom in increasing order, instead of each side and around the center of the panel.
Example (for a panel shifted towards the top of the window, with buttons added from top to bottom):