Assuming you want to stop, and not pause a multi_manager:
If you have a method to fire logic when the player dies (perhaps try the method with trigger_multiples and counters I mentioned above) then yes, you can do that.
It will be complicated but it would work:
My memory is that killing a Multi_manager causes a crash, so....
The basic idea would be that you put something between your multi_manager and the things it is targeting which can be switched off.
So your multi_manager(MM) should be set up like this for each output:
MM --> Trigger_multiple ----> Thing you want the MM to target.
(you could use lots of things in place of that trigger_multiple, take your pick, but use a new unique trigger_multiple like entity for each output the MM is making).
Now, once your MM is all set up and running fine with that method do this:
When the player dies, use multisource(s) to lock and disable all of those trigger_multiples you made. By doing that, the MM will effectively be stopped.
Alternately, you can kill them with trigger_relay's, but they wont work again until you reload.
lastly, you could theoretically pause the action by not using a MM at all, and just making a string of triggers and entities that go from one to another.