Have done with Altiris - created a task\job for IDER boot (both forcing PXE and defined DOS ISO) - and successfully booted 4 of the 5 systems in my lab. The 5th system that didn't boot appears to have a firmware issue.
If planning multiple IDER sessions - have to reboot between each. Haven't done a network\services trace - yet it appears the connection between the server and the vPro\AMT system remains from the IDE-Redirect session until next system boot. This makes sense since by definition the IDE-R boot overrides the client's BIOS boot order.
Also - noticed that if I tried to force session, after session, after session... eventually the server starts to be the hold up. Working with a virtualized server environment and have resource constraints. During one IDER test - the client systems didn't appear to respond. However - when I reset the virtual server environment, the queued up jobs commenced once the server completed loading\logon.
haven't stress tested how many concurrent IDER sessions can be run
After remotely Power-Cycling the clients from the SMS collection container, i could get 10/10 clients to launch IDER sessions.