With Sxi-q you draw a power curve with the computer, and transfer it in the mod. Problem is, you need to experiment with vaping while the computer is connected.
A suggestion. If you are deciding between a Yihi and a DNA, go for a DNA.
In 2018, Evolv released a totally new device (actually, a software) which is Replay, that changed the way many of us vape.
Yihi in 2018 innovated with a fidget spinner on their new mod, and was the only addition.
We haven't seen anything new from Yihi since the 550 (G class). Draw your own conclusion.
EDIT.
You may have noted from technical reviews that Yihi mods - in Watt mode - are routinely overpowered of more than 10%.
That is, if the mod is set at 50 Watt, it is truly delivering 55 Watt to the atomiser - and sometimes more.
This seems done on purpose (this is an opinion, don't quote) to feed the mith of being an "Hard hitting" mod among some Vapers. To me is a deranged device.
Also, there is the little issue of warranty. Evolv will fix any mod with their chips; their boards (and screens) are commonly available from modmaker shops.
With Yihi is the polar opposite; on top of it, they have a much reduced warranty on the USB port, as their ports fail easily.
I have both Yihi and LV mods. I do prefer LVs for a number of reasons, and my preferred devices are the 75c (I know this is controversial).
Yihi mods excel for their conversion efficiency, generous circuit overengineering, great fire button, great aesthetics and a magnificent 510.
They kill the batteries while on standby, tho.