Here's some more stuff I've played around with at 16's bridge.
I can stop the bridge collapsing so Agro and Wander can ride on it as normal. I tried making Agro jump back to the ledge they started from but he just falls into the gap.
Also Agro survives sometimes when he lands on this invisible ledge, but only when the bridge is locked.
I can stop and start the bridge collapse so it seems like time has frozen ; )