Note that this is my own opinions which probably are a bit biased. At the moment there are no built-in missed task launchers but it should be fairly easy to do such by creating a condition that checks the task run periods and whether the task did not ran the latest interval. This is not hard to do but the problem is that I haven't had time to document the time period utilities which are actually pretty extensive. I have plans and some prototypes to do pre-built a misfire condition which one can just add to any task using the OR operator.
There are 3 options for concurrent tasks: async, thread and process. Just change the execution argument of a task. Choose which suits you and remember there are pros and cons in each. All of them supports parameters etc.
How does it deal with concurrently scheduled tasks and the possibility of missed tasks?