I only recently upgraded to Accordance 10. In previous versions, I was able to open a new pane/zone with a specific resource (not amplifying) by holding down the control key while choose the resource from the Resources palette.
This does not work on the toolbar, as control-clicking pulls up a contextual menu, as it should. I've tried several other modifiers, but so far I've not found any way to open a resource from the toolbar unless I'm amplifying.
For example, today I wanted to open the Cross-References tool to do a search. Every time I tried to do so from the toolbar, I got an error stating "A verse reference selection cannot be used from any tool."
I know I can open the resource from the library pane/popup, but I keep my library hidden, whereas I have icons for all the major tool groups on my toolbar.