Yes, but my point was that 1.x addons are not compatible with OH 3.0, so for the OP to implement something now that makes use of them would be creating rework when they plan to update OH. If the OP is planning to stay on OH 2.5 forever, then certainly the expire binding is also a suitable option.
I believe you are mistaken or do not have the full story on expire. A 2.x version of the expire binding has not been created because it was a mistake to have let a 1.x version into production in the first place. It’s pretty clear that a 2.x version would have not been approved. There are plenty of discussions about this in GH and the forum.
While it is unlikely to be in use in a production sense, it’s definitely being used in development. As for being clearly defined, a software product is only ever truly defined until after it is EOL. Coincidentally, the expire binding has only just become clearly defined 
! OH 3.0 is in it’s infancy, but the major focal points are UI, automation, Java 11, and 1.x compatibility.
Yes, absolutely… cron triggers and the createTimer Action are both currently available in the new rule engine and I do not foresee or plan any change to that.
My point exactly… although knowing how to use cron triggers and Timers are skills that will still be useful in OH 3.0. There are several options that the OP can choose from, but the OP needs to decide whether they want to implement a solution using cron triggers now or when they chose to upgrade to OH 3.0. If the latter, they also need to put effort into implementing expire in the interim.
I don’t understand this… cron triggers and timers have been around much longer than the expire binding, and they have outlived it! They are solid tools to use for implementing this sort of solution, so I recommended the OP use one of them rather than something that will not be usable later this year.