I'm so sorry I haven't answered any sooner, but frankly I've never seen the comments on my profile, only the ones for each video. Regarding your question: The redirecting Stargate doesn't really turn on at the SAME time, but in fact a few milliseconds later. That's because I wired everything together in such a way that as soon as the DIALLED Stargate gets active the redirecting Stargate immediately starts to dial.
I.e. I took the output "active" from the dialled Stargate and used that signal in an expression gate to start dialling on the redirecting Stargate.
I don't know if this helps you anymore after all this time, but here's the answer nonetheless. :)

in your videos about redirecting stargates, how did you get the redirecting stargates to turn on? I've been able to get all the other things to work (closing gates with keypad, the redirecting part, etc.), but I can't figure out how to active all the needed gates at once.