Hi Pat,
we had the same problem as you, one thing is very important.
-----Never create more than 600 dependencies, this will greatly slow down your Application ( edit a node within 50 sec and more )! ------
We had to create "device" Groups and then build the dependency for each group - not for each Device!
Sample:
A Group for Routers (dynamic filter or manually assigned) and a Group for other Devices (dynamic filter or manually assigned)
Then build Dependency
Group Devices depend an Group Router
Now when the Router stops responding or WAN is down, the Devices will stop reporting and have the status "unreachable".
They will report again when Routers are up agein.
br
Alois