Yes I tried both solutions, but solution No. 2 is not really one, rather a workaround, because as you said it will break all double taps in the scene. It's also not a good practice to change the detection time for double taps only to let single taps not swallow touches. And it doesn't solve the root problem: Being able to choose for each single object whether (A) to use single taps which cancels themselves when a double tap is detected or (B) to get informed about each single tap regardless of any further possibilities for double taps.
It's a nice solution tough, if there are no double taps in general, but in a usual case you just don't have double taps on a specific object, but on others. So solution No. 1 sounds more promising for me and any future projects. It's only the question now how to distinguish as easy as possible between lifting on an object and off an object. And how to do the same in conjunction with PlayMaker.
BTW in native iOS you have also a gesture recognition system, but there you can wire up different gestures logically together. So single taps fire immediately or you add them to a double tap gesture requiring it first to fail before the single tap can fire. With this the developer can choose which case to use for a specific object (A) or (B).
And with "For me this looks a little bit odd compared to the more streamlined simple tap events" I meant there is such a nice integration of Easy Touch in PlayMaker for simple taps, but not for the TouchX events. For simple taps I can easily add global and local transitions, just by right clicking on a state. For Touch events I have to rely on an action which blocks and then simulates a local transition. That's all.