This will be superb for a aspheric flooder. Not a thrower. The die projection will be extremely large. Nice find however.
My optics knowledge is, let's say, newb level.
Flintrock, my light output estimations are based on the typical spatial distribution graph which can be found on Cree emitter datasheets, and I presume the x axis reference to be the center of the die. Sounds right?
Well, I've inspected the lens which came with my in the works cheap zoomie overhaul: ∅29/27mm OD/ID, with an estimated focal lenght of ≈20mm; sounds right, as the led was sitting close to 4 mm below the lens plano surface, and the head travels slightly above 16mm.
It is clear to me that, with an XHP70 below, the new lens will sit over the dome unless I use some sort of spacer/support structure.
I also have this option: https://www.aliexpress.com/item/Free-shipping-High-quality-high-transmittance-led-lens-35MM-diameter-optical-glass-lens-mirror-lens-power/807856981.html
On the zoomed in position, captured led output angle is 2 × atan(16/17) which equals 86,528590822143°, for an estimated ≈68'62% of light throughput through the lens at such a distance from the emitter. Less captured light in zoom mode with this lens, but the emitter projection should be sufficiently smaller to be more intense, doesn't it? Well, this lens is 1,5873015873% wider, diameter wise, than the thicker one. 
Cheers ^:)
Sounds like how zoomies work to me. I forgot to add in my post above that for throw as the lens is farther away it should of course also have a longer focal length. Anyway, however big the lens is, it always becomes effectively bigger when you move it in close, just out of focus though if too far in(but that's the point), and yes, less intense in spite of it.
The way I usually explain that to flashlight noobs is that in the 3D space inside a reflector, there’s a focal point, not a focal plane.
The same way pulling an LED or incandescent filament farther away from that point in a Maglite defocusses the light and makes a hideous ring of light instead, the smaller the LED chip, the closer to that ideal point is the entire lit surface of the chip, whereas a larger chip has that much more of its surface farther away from that point, so naturally is “blurred” somewhat compared to the smaller chip.
The same would apply to focussing light to a point from parallel rays through a lens. Only you’re doing it backwards; the focussed point would be the light source, and parallel rays the output beam.
Well, actually though there is a focal plane, or a focal surface at least, that's how cameras take a picture, but the point there and here too really is that that picture taken from the camera is a picture of everything, light coming in from all directions (and if turned around as a light, would go out in all directions).
There's a focal point for beams pointed straight out of (or into) the lens, the beams we want for throw which is really your point and the important one, and yes, this is often simply referred to as the focal point of the lens. However, there are actually other focal points on the focal plane for beams headed toward, or coming from, elsewhere. We just don't want those for throwers.
Anyway, what I tried to capture is not just how a big led gets de-focussed, but why a big, farther-away, longer focal-length lense, compensates for that.
Geometrically a big lens or a small LED is the same. It's like taking the same picture and just blowing the whole thing up with a copy machine. Angles don't change when you do that, so you can have that big LED, so long as you blow up everything else too, lens and focal length. But it's all saying the same thing.
Well, since I am to focus a quad-die emitter, a not so sharp focusing may actually be a nice thing.
I'd like to have an idea of how the thick lens' light cone would be. I'm guessing that, in flood mode, it would project a relatively narrow angle cone of light due to the powerful beam convergence, fed with 94+% of the led's total output. And of course, it won't be a champion of throw, yet should project a pleasing, uniform, efficient light-full corridor. 
:-) :-))
Cheers ^:)
I know, but I qualified my statement with:
“The way I usually explain that to flashlight noobs is that in the 3D space inside a reflector, there’s a focal point, not a focal plane.”
Everything else, agreed.
Yes no disagreement.
Looks like a… :FACEPALM:
Cheers ^:)