By "SDS" do you mean "System Default Settings"? Or something else?

One way would be to add a check for the existence of a process-private global (PPG) node. Something like this:

lock +^TEMP("FOO"):0 //don't wait
quit:'$test
quit:$get(^||CRITSECT("FOO"))
set ^||CRITSECT("FOO")=1
//critical section
//...
kill ^||CRITSECT("FOO")
lock -^TEMP("FOO")

FYI the most recent beta VSIXes of Server Manager and the ObjectScript extensions now do their best to end web sessions when they're exiting or restarting.

The relevant versions are v3.10.1-beta.2 and  v3.0.2-beta.9 respectively.

A similar change in the Language Server extension is being prepared.