... But whether I'm using a 600 EX-RT or Yongnuo YN-E3-RT as on-camera master, I use the in-camera External Speedlight Control menu. Just seems easier & quicker to navigate.Good tip. When I'm shooting in a multi-flash environment, my camera is always tethered to a laptop running Canon EOS Utility, which is a great tool for adjusting flash settings on the fly (and saving them for later use), but I will have to check out the in-camera Speedlight menu.
If in-camera External Speedlight Control is something you use, then make sure to add it as a My Menu item. It surprises me to find out how many Canon photographers are not using the My Menu function. It is the one I use most often, rarely straying into the main menus. In the camera menu settings if you move all the way over to the right you will find a green star with the title "My Menu." My contact at CPS woke me up to My Menu when the 1D MkIV first shipped.
What this allows you to do is set up that page so that you can put your most accessed menu settings on one page so that when you press the menu button it will take you right to a page of those menu options. That way you can access them quickly without having to try and page through your menu system.
What I'd prefer would be that the Q menu was customizable. I'd put External Speedlight Control there.
but already in "my menu", the flash controls went in the same day it arrived!. saves SO many button presses
And now I'm waiting a couple more weeks for my photo fund to get fat enough for the 2nd flash.. so thanks to everyone for your input. (damn, hate having to be patient)
RE the 430EXIII, I did stop and look at that, it's close, but it's almost a stop less powerful for twice the cost (58m vs 43m @105mm)
Having a single flash on camera right now did force me to try something that worked enough to use: I discovered if I point the flash up 45 and rotate one side, about 90~135, zoomed to 200mm I can semi create the classic off camera flash portrait look, but not as good as the background gets too much light, but still for on camera flash without a brolly it isn't bad.