I don’t mind the moon memo at all, but yes, I noticed the D4S had some user-requested changes in its simplified version of your new firmware. I’m amazed at how far a one-button interface can be pushed. Certain other products seem to resort to bluetooth remote control long before this, but then they’re over $100, mostly rubber not metal, and have much bigger markets.
If you are interested, and don’t mind a little soldering, you could upgrade your D4 with much more interesting firmware.
I am interested, but not too excited about what it takes to remove the driver and buy enough bits to grip the chip. I’m an EE and electronics hobbyist so I certainly could do it and won’t rule it out, but it’d be a relative lot of stuff to get that as far as I know I’d never use for anything else. And, I don’t think I’d get it back together quite as nice with the paste and everything. I think it’s that I only like taking apart stuff that is an extra one, something I don’t care about breaking, or don’t intend to ever put together. I’m not into modifying one unit of something I like. The D4S with the exposed pads is a more likely target, though. The lightning and candle features I could add are definitely tempting.
If it shows where my interests lie, I was willing to spend about the same money as the flashing tools (I think, ~$30?) for the clamp meter. I figure I will have other uses for that, though. Maybe. Wish it would measure AC power without having to clamp only one wire in a power cord.
I wrote a few hundred lines of C firmware for a Cypress PSOC based USB light meter, but when I look at the Arduino code for the instrument at my new job, it’s pretty intimidating. I see it call “avrdude” at some point and thought of this thread. I still like 1990s BASIC with line numbers. Did everything I wanted for much more complicated programs than these, and never gave me bugs from unintended variable type casts or overflows.
Anyway, the flashlight isn’t for tactical or practical purposes, and I have lots of light-up toys, so I’m happy to have it for what it is in stock configuration. If I ever look for a 2nd one, though, or a new version (D4X?), and expert-mode firmware is a paid option, I’d probably go for it.