I do not see how I am "spiritualizing" Matthew 24.
When I use the term "spiritualize", I mean something very specific: taking some scripture text that describes something about the world and concluding, without evidence, that the desription only applies to some "non-material" sub-set of that world.
Do you see what I mean? Example: The Bible tells us that Jesus has been installed as king of the world. To "spiritualize" such a teaching is to assert that He is only king of an an unseen "spiritual" domain, and is not really king of the very real insitutions of this material world.
I hope this clarifies things. In this sense, to suggest that Matthew 24 has already been fulfilled is not to "spiritualize".
Personally I would use the concept of "non-verifiability". If we understand Matthew 24:30 in a traditional way--that it speaks of the 2nd coming--then such an event is ultra-verifiable. You can't miss it. You aren't going to miss the "end of normal history".
As interpreted under partial preterism, Mathew 24:30 speaks of people supposedly recognizing that Jesus has been vindicated, maybe enthroned I think, or that he came "in judgement" on Jerusalem. So we are talking about things on an invisible spiritual level. (The destruction of Jersualem itself is a solid real-world verifiable event, but any supposed "spiritual" "invisible" coming of Jesus isn't.)
So to me, it looks like taking something solid and verifiable (on a traditional reading) and instead reading it in a way which has fulfillment supposedly placed in a spiritual realm.
I ignore in this post the question of whether you have good evidence for your interpretation.