The Parameterized Scheduler plugin only work for one set of parameter. In other word, I can only enter one line. The next lines are not used.
 

Reproduction steps

1. Create a task with one choice parameter "PARAM" (item1, item2, item3)
2. Then define the following line in the Parameterized Scheduler Plugin:

   H/2 * * * * % PARAM=item2
   H/3 * * * * % PARAM=item3
   

3. Save the job and wait for the builds
    

   Actual result 

I get builds for 2 builds per minute for item2 . But don't get any builds for item3.
But sometime vice versa so there might be a random line chosen here.
 

Expected result

I should get 2 build per minute for item2 and 3 build per minute for item3 as defined in the cron.