The Link on the first post doesn't work... the one 2 posts above just gives me the one that doesn't work.
Try Shift+Enter
It sets to a default, Shift+Tab. By setting your own key-bind, it saves a file in
config/client/rtb/prefs.cs. To change it without opening it, press Ctrl+F (Cmd+F on Mac), and type in
$RTB::Options::OV::OverlayKeybind. Change the "..." in
"keyboard\..."; to a simple key-bind (one key, such as A, S, D, F...). Open the overlay with the new key-bind, go to Options/Settings or whatever, and set your new preferred key-bind, (such as Ctrl+Backslash or whatever).
