Well, this is certainly one of the rare times that I have heard that a customer can not wait for 3 minutes for a workitem. Anyway, you can set up case specific deadline monitoring (SWU3). If you use that, it will schedule a job for each work item. This way the job will execute as soon as the deadline expires and thus trigger the workflow. Please understand that this may have a negative impact on the performance of your system if you have a high number of jobs triggering constantly. Having said that, if this requirement is important to your client, then they may be willing to 'wear' the performance hit.
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