Note: Don Preston is a full preterist and therefore his teaching cannot receive full or blind acceptance. His many videos on YouTube are worthy of listening and interacting with in a timeline manner.
@1:20: This is a decent question. The song is "for many generations" but is also "at hand". These type of conflicting time frames can be distracting. The idea that Preston presents as "projected eminence" is pretty important. It is important to keep in mind throughout the Scriptures.
@3:43: This is an interesting idea. The speaking prophet speaks as if in the "last days". The Isaiah reference to new creation is a good example as well. There will be an interesting debate now about what type of "projected eminence" Peter and Paul perhaps used.
I did in fact contact Mr Preston about receiving a free copy of the book Can God Tell Time. Perhaps I'll set up some time to review it in the future.