I didn't say it was difficult, as in hard to remember (though I've heard people say that) - it's unintuitive, and requires more presses and more combination of modes than it needs to. I already explained why, and why a simple menu structure would serve much better: scrolling upwards through temps to turn TC off, but downwards to change from C/F is a particular example.
I would love most complex mods to have four buttons not three, but even with three buttons there's opportunity to make things relatively simple and intuitive. And not requiring locking the mod before accessing most of the functionality. And having the ability to go in and out of TC without losing the temp setting. And not require losing one feature to add another (power lock gone for atty lock). And allow adding any number of other features at any time. Etc etc.
There's any number of good UIs around you every day. The applications on your computer, on your phone, any simple device like a car dashboard, a microwave, a radio even. Good UI works on the principle of "least surprise", of clarity. A menu is a very familiar, well understood system, which allows congruence of like facilities into a relative minimum of control actions. It can be updated at any time for any number of actions; it can be hierarchical; it can be self-teaching.
As I've already said, I don't direct this exclusively at Evolv. Yihi did implement a menu but it could have been a lot better. Dicodes did a great job with one button, but it would have been a huge lot better with two, which they could easily have fitted, even in a tube. We'll have to wait for their box mod to (hopefully) see what they do with a good menu and the right number of buttons to begin with.
No-one is doing it "great" yet. But I can point to many that are doing it better than the DNA 40.
The DNA 40 would be a better mod with a menu. That's my view, and I think the view of most who think it through (objectively.) At most you can argue it's not worse with the current system. But even that is shaky when the current system has already required the drop of one useful feature, and the inability to implement another (memory of last temperature setting when switching in and out of TC.)
And not least because, how do you propose they ever add more features with the current control system? Surely no-one would claim the current number of features is the perfect number? The DNA 40 has a whole lot of functionality that's going to be PC exclusive, immediately locking out Mac users and anyone who doesn't have or want to use computer software. Some of that at least could definitely benefit users being on-mod, not to mention other features as yet unthought of. How many different button combinations do you think can be supported by the current system? We already saw with the DNA 40 it had to lose one useful feature (settings lock) to gain atty lock. I just don't see how anyone could claim that's "good" - nor why anyone would claim menus would be worse, when they demonstrably would take no more, and often fewer presses to operate, and they already use them to great effect every day of their lives.
Please don't fall into g's fallacy of "if this is how it is now, it must be the best way." That is the enemy of progress, and is immediately shown to be false as soon as the next, better product comes out. I want every product to be as good as it possibly can be - Evolv most definitely included. We can accept shortcomings, but should never excuse them except as short-term practical compromises. We can and should always strive for perfection wherever possible.
Outside of adjusting a pre-set memory? How? And does it require tilting it left and right?