you always terminate the last item in a dmx chain.
if you have a cable leading out to another device from an aether II's, mr16, freestyle, ssr4, or the DMX OUT1 of an express, then you don't terminate.
if you don't have a cable leaving this device to go to another device, then you terminate.
if you use a dmx splitter to split the signal, or the DMX OUT2 from an express, you just now created a new dmx chain, and the last device needs to be terminated.
if you're using wireless.
each express that receives the wireless connection is starting a new dmx chain, so like above, if anything is connected to the DMX OUT 2 from the wireless express, the last device in that chain needs to be terminated.
for example, if you have 100 Expresses all receiving their signal via wireless, and each one has a SSR4 attched via the DMX OUT2. all 100 SSR4's would need terminated.