Hello Nate,
> Sometimes (recently) I have quite a few custom agenda commands and if
> the window is not large enough, I can't view all of the available
> agenda custom commands - what is the keyboard shortcut to scroll /
> display the lower section of the custom agenda commands?
AFAICS there are no commands for scrolling for that case yet. FWIW in
branch "master" (and "next") C-n, C-p, SPC and DEL work in the agenda
dispatcher like in the export dispatcher, hopefuly.
Possibly { M-x customize-variable RET org-agenda-menu-two-columns }
can help ease your case somewhat if you don't use master.
Ciao,
--
Marco
