There's no doubt that the DZ-1008 was designed for the DZ-1000, I have to trim the leads sticking out of them to use them on the DZ-2500's. 
I haven't seen any of the delay issues that cause shorts because of slow switching where I used the DZ-1008 relays with the DZ-2500 switch machines on my layout. I have them on all of the 072/096 curved switches and the two double-slip switches. I've transitioned the curves switches at 60 scale MPH and the relays switched long before there would be a problem with the switched power to the rails. It's very unlikely that I'll ever be running faster than that speed, so I think I'm good.
Trying to thread your way through the DSS at high speeds is an exercise in futility in any case, so I certainly don't see the relay speed as being an issue there either.
