Is it possible to decrease the interval for SAL Scheduler below one minute?

[Morten Stokkereit Johnsen]

We have a custom add-on which we would like to run faster than once a minute, ie every 10-30 seconds depending on which environment it runs in. Changing the interval above 1 minute works fine, but whatever we set below 1 minute just defaults back to one minute.

I've seen the link for runnable with concurrent, but it seems odd to me that below one minute doesn't work as they provide examples of exactly that in the tutorial.