Let's dive into some Science Fiction now.

One of the major reasons of disagreement is the button functionality. That could be resolved making the internal controller programmable. So you just connect your flashlight with the USB cable to your PC, or establish a BT connection with it from your phone, start an app, and build the button-light behavior in any way you want, or select a ready made profile from the list, or even download it from the fan-site. It could be even possible to have a button command to change the profile entirely to another one without connecting to the app (i.e. changing it as the changing conditions dictating). Even better yet - make the light controllable from the phone directly too! I believe I saw such a flashlight in a prepubescent stage at least announced a while ago.

The second one is the battery. To me it's obvious that it must be removable/replaceable and rechargeable. For us, ETS folks, always tending to carry a spare battery, most likely a LiPO with integrated protected charge pump would be ideal. When depleted you just replace it with a spare and setup the empty one for charging from an AC/DC source, a powerbank, the sun, or some standard battery found or scavenged. That would work well for those standardized on AA or CR123, or not standardized on anything but USB port.

The shape/casing must undergo the same transformation as the one of the modern smartphones. A minimalist functional battery+LED+button+charging port(maybe) capsule, and infinite possibilities for the replaceable outer shell (waterproof/shock proof to any rating wanted, any mount type required, extended external battery, integrated solar charger, and what's not).