Interesting...

none of my blitzes incorporated this tactic.

You indeed discovered a loophole I've never seen before. Since I didn't explicitly prohibit the usage thereof, and other tactics which are similar are used, you may consider this a legal maneuver.

But what is totally bizarre is I am this close to beating your HRE record with 8 turns... without using that trick.

I can't imagine what I will be capable of with this trick.