It would be helpful to have the Read Uncommitted listed as a global runtime setting.
Most of the workflows I design need this set, so rather than risk forgetting to click this option on one of my inputs it would be beneficial as a global setting.
For example: the user would be able to set specific inputs according to their need and the check box on the global runtime setting would remain unchecked.
However, if the user checked the box on the global runtime setting for Read Uncommitted then all of the workflow would automatically use an uncommtted read on all of the inputs.
When the user unchecks the global runtime setting for Read Uncommitted, then only the inputs that were set up with this option will remain set up with the read uncommitted.