While I'm at it TD, you might be interested in knowing about the general type of light I have in my hand and am currently playing with in my LR. The primary reason is that, within its area of light radiation / distribution pattern, it has what I would describe as exactly the characteristics you've emphasized repeatedly, in this respect:
The typical radiation patterns of most conventional 'reflector' based lights (or LED variations thereof), emit a central 'hotspot' (which may or may not be an evenly-distributed light pattern within it), then in concentric circles or rings, that is often followed by a 'corona' area, which is then often followed by an area of 'spill' or flood; quite often with very uneven distribution of light across all of those. The light I have here projects what is essentially a perfect circle of light, with absolutely homogenous and consistent / even illumination within that circle, and which has a well-defined outer boundary with practically no 'spill' outside of it. Think of it as one large circular 'hot spot', with homogenous and evenly-distributed illumination out to its boundary, with no real 'spill' or 'flood' area(s) per se. If this one had a lower color temperature (as higher ones like this tend to wash out color / shading details, and also produce much more 'back scatter' due to predominance of shorter wavelengths, which is due to detrimental reflections from aerial haze / particulate matter in the air such as high moisture / humidity levels as are common in your area, particularly at night and in low-lying areas) , and if it had decent 'color rendition' (which it does not), it would probably be exactly what I'd want to use for near-field terrain searching like you're doing.
This light uses a version / type of an increasingly popular type of output management setup commonly referred to as a 'TIR' optic (as in Total Internal Reflection, of fiber optic transmission 101 fame). There are many different specific designs of 'TIR' optics (often utilizing a variation of a reflecting surface(s) and / or a sometimes complex front 'lens' to optimize specific characteristics (for both single and multi-emitter applications) produced by companies like Ledil, Carclo, etc.). Someone more familiar with the current flashlight market than I am may be able to direct you to some photos which illustrate this kind of optic and its characteristic distribution pattern, and perhaps production light(s) incorporating them. I would also, again, recommend something with an appropriate CT (say, 4000-4500K), and relatively high CRI.
Since the one I'm playing with reminds me exactly of some of your descriptions, I thought I'd mention it. Some variant of this could provide ideal illumination characteristics for you.