There is a mechanism by which you can solidify some of the scheduling issues in SmartThings, the ones involving repeating schedules, such as polling. The mechanism is to give your system an external time source.
My setup happens to have an Arduino / ThingShield, for my Lutron integration. It was trivial in the Arduino sketch, and the ThingShield device handler, to put in a once a minute message from the Arduino. This is not clock resolution timing, for sure; but it is heartbeat timing that is rock solid. I would not recommend running something like this faster that once a minute.
I have mine set to toggle a virtual switch. I can use that for other purposes, in Rules.
You could build this out of any Arduino / ThingShield pair, including Uno, Mega, etc. It costs $80 +/-.