Tagging @jamesguitar3 with the feature suggestion. 
In the meantime, you could use an approach similar to what @marktr suggested in this post for looping.
I’ve sketched up a version of it in the following graphic. The main difference is that the Virtual Contact is turned back off each time it is opened which enables you to use the Virtual Contact stayed off 30s as a trigger in a second SharpTools Rule to act as a recurring timer with a rule flow that conditionally checks if the Virtual Switch stayed on during that same 30s period.
If the switch also stayed on during that 30s period (as a condition in the rule flow), then you start the cycle over again by opening+closing the virtual contact… otherwise if it didn’t stay on then the cycle dies.
Notes:
- Blue boxes are triggers.
- Orange boxes are actions
- Grey diamond is a conditional in the rule flow