what can replace splitUsers scenario injection setup option from Gatling 2.2?

I would like to create a Jenkins capacity job where the user has the option to choose the ramp up “slope” only
but the test itself is set to keep on ramping up and run “forever” until the environment gives up. (capacity or environment limit test)

On Gatling version 2.2 I had the following injection option which would give me what I need:

  splitUsers(1000) into(rampUsers(10) over(10 seconds)) separatedBy(10 seconds),

I can expose only rampUsers and over in Jenkins while I keep splitUsers hard coded with a very high number which I am not really planning to achieve.
This would give who ever runs the test the ability to control the ramp up while the actual test and number of users will run until failure.

Unfortunately this option is not available on the latest version of Gatling. Is there any other way to achieve this?