However... it would be good to check what type of regulator you have. If it's a 2 battery mod (like a box mod) and it is using a linear regulator... that's a bad combo at lower voltages. The greater the voltage difference from source voltage, the more you drain the battery.
So... for lower voltages like that.. I'd stay away from linear regulators. The buck/boost would work, so would switching regs.
If I were you and was using those low voltages all the time... I'd change the atty/carto at will and just go unregulated with a protected battery. Simple, compact, inexpensive, easy to replace. But that's me. It wouldn't be regulated and would follow battery voltage. FYI - The eGo units are PWM regulated so they kind-of regulate to a constant 3.4.
One thing about the madvapes vv box... if you vape by numbers (as I do) and change voltage frequently thoughout the day (like you do) it's hard to set the voltage on a vv mod that has a wheel and no voltage readout. There are lots here that don't want to see numbers and prefer to "dial to taste" and that's fine. But I can't do that successfully.. I've found that (for me) dialing to taste gets me a burnt hit all too often as the wheel control devices that I have (madvapes box, Sgt army tanks and VV Reo Woodvil) have no play in the wheel.. a tiny turn of the wheel can turn the voltage up too high or too low. It much easier (for me) to just tap a button and set the voltage to what I want. (To each their own.. I don't put down people who prefer to use a wheel so I don't want people putting me down just because I prefer not to set my voltage without a readout or a voltmeter.) Like I said above, I take my VV madvapes box to work because it's convenient but I don't often change the voltage on it.. I usually keep a 3ohm carto in a tank on it at 5v. I use a diy caramel capp mix daily and this is what I use it on.
so consider that when you are choosing a vv device. Do you want to "dial to taste" or do you want to know the numbers. Neither is right or wrong, just preference. at the expense of sounding like a provangelist... the provari mini is very small, easy to change voltage, shows the correct voltage and the voltage is consistant to the very end. It may be on the expensive but it's not a disposable device. It has a year warranty so you get free repair for a year and if you spend another $25 at purchase, you get 2 years of free repair.
I really, really want one of these. She's not gonna make any more? That's sad...
To get performance and battery life you either need size or a pretty expensive custom built mod. The main problem with a mod like in your vid is you would probably need 4 of them to get you through the day. So which is bigger? 4 of those or one mod with a decent size battery.
There are people around that can build you one something like this .......... if you have enough cash............
I guess the OP has to guess who these people are and have plenty of cash. Or you could be trolling for business, which is not allowed on ECF.
OP: I don't know what "I have an eGo so not a box mod" means.....
I'm talking guts here... not shape or specific mod.
Also, IDK what is wrong with the twist you have? Too banana? I only mentioned the eGo since 1) you have one and 2) it's PWM regulated... fairly consistent.
You figure out shape issues on your own. The point is...check the electronics inside of whatever you select.
I still like this one (or similar mods using a switching reg):
Specifically why I didn't mention any names, I know several that do make & sell mods, but it's up to them how and where they market their products. And, I have never nor will I ever make a mod for sale.
However Click-Bang and Mamu are well known here on the forum, and their contest has been well advertised.