Control scenario duration in profile


I would like to play a scenario like this:

setUp(scn.inject(split(1000 users).into(ramp(100 users) over (30 seconds))
                                  .separatedBy(30 seconds),
                 nothingFor(10 minutes),
                 rampDown(1000 users) over (30 seconds)))

And the scenario would be like this:

scenario("something").asLongAs(true) { ... }

The idea is that `rampDown` would kill users and the scenario would run
30 minutes.

Currently, I need to generate several scenario to achieve the same
effect (I could also use a feeder to get the same effect with one
scenario but the point is that I don't want to use during + a dynamic
duration to get the rampdown effect):

Is there something possible (using a dynamic condition for `asLongAs`?)?

The inject DSL is for injecting, it has no control over the users’ life duration.
If that helps, Gatling master has a maxDuration set up for shutting down after a given duration since start up.