Got it down to about 70 seconds.
That leoparding is beautiful. Out of about 300 attempts, you're about the 3rd or 4th person to break the 90 second barrier with an LBE. That's a tremendous feat. I've been recommending large and low stone ceilings for quite some time now, and I'm happy to see the theory turned into reality.
That being said, while your top browning looks fantastic from a NP perspective, your deflection/bottom browning needs work. The V shape bricks have got to go. Between the brick and the 13" deflector, you're seeing uneven heating of the hearth (see screenshot of one of your previous pies below).
I've been talking about deflectors needing to be either the same size or larger than the hearth long before the blackstone came along, and now that we've seen what the blackstone can do, there's no question about the importance of larger deflection.
It's not the easiest thing to source, but for ideal deflection, you want some kind of steel pan that's slightly larger than the hearth, positioned under the hearth with an air gap. If the pan is heavy enough gauge (as with the BS), the stone can sit on it, with stainless steel washers to provide an air gap, but if the pan is lightweight, due to the potential for warping, the pan has to be suspended independently of the hearth.
The blackstone is a both a blessing and a curse to aspiring LBE owners. It's a blessing in that it showcases exactly what's required to achieved the necessary thermodynamics for very fast bakes, but, it's a curse in that it will draw many potential LBE owners away from the LBE and hamper experimentation. It won't, obviously, replace the LBE. Between the stones, grill and burner, an LBE can be put together for as little as $150. For DIY people, $150 is a lot more attractive than $370. In order to really compete, though, we need to start seeing this 1% very fast bake success rate increase- which, due to the knowledge garnered from the BS, I believe we're going to start seeing.
The biggest barrier, imo, to increasing the success rate is standardizing the modifications in some way. If someone's striving for NY, there's hundreds of approaches that work, but if someone wants NP, then there's not of wiggle room on configuration.
We can recommend:
High pressure burner (90K+ btu)
Two 19" kiln shelves (one for hearth, one for ceiling)
Steel lazy susan
Dremel for cutting vent and opening for burner
and those are all relatively easy to find/order, but deflection, so far, is, unfortunately, a lot more piece meal. To date, deflection has been more about finding the right item rather than ordering it.
Deflection doesn't need thermal mass- you just need something to put in the way. I can't speak for durability, but galvanized steel flashing can easily be found (HD/Lowes), and a multi-day vinegar soak has been proven to be very effective at removing the dangerous zinc. It can also be cut into any shape you need with tin snips. You can also use this flashing in a ceiling disruptor role like Chau did in the BS.