Add a "match circuit" command.
Make the "Select Circuit from Drawing <" button a command that can be typed into the command line. After this command has been run, do not show the Circuiting window, instead go immediately to "Circuit Devices <". The user can then continue to circuit additional devices to the circuit they selected. A double right click would bring up the Circuiting window or the user could escape out of the command without showing the window.
Yes, this would be much like "match layer" command. It would save time not having to follow loops to find a home run or query-ing a device to find out the circuit being used in the area already.
Click the device you want to circuit and add it to another devices circuit by clicking that device.
Aaron Dennington commented
A slight variation or clarification - after "Select Circuit from Drawing" has been clicked/run, the next user action would be to select any device on that circuit to identify which circuit to use.