Nic salts at that high concentration are usually used in super low power devices such as pods (think the juul which can go up to 59 mg/ml but it's engine is WEAK. Folks don't get nic overload (as much) in those types of devices.
If you stuck that in oh, say a Nautilus 2 tank, even, you might be more likely to get nic sick as (while it's still a MTL device) it's wattage output and vapor output can be more.
There is a place for said devices, and it is in the stealth realm in my opinion, or during times when you can't vape a lot and need a quick "fix" during breaks.
However, you MAY be able to go higher than 12 m.g in your current setup (which you still haven't told us what it is, yet, BTW, and that would be useful) but how much more is going to depend on your vapor output per puff.
Nic salt vendors of premade juices many of them, are selling a slightly cheaper option of juice to refill pods and whatnot, which is why they are often made at that strength. They do it because it's what the market supports.
You can vape nic salts in any device, at the correct nicotine LEVEL as was pointed out, some folks just plain prefer nic salts, even in sub0hm devices, at the right nic level.
There is no "magical" device MEANT for nic salts, where if you use freebase your coil magically dissolves and catches fire, there just ISN'T. I am SO TIRED of dealing with that marketing nonsense. It creates confusion and uncertainty.
And just because you can obtain a 50 mg/ml nic salt juice doesn't mean you SHOULD vape it in even some airier more powerful MTL devices than cigalikes.
I'm sorry but just forget everything you've been told or read, it's all marketing BS so just increase your nic salts sloooowly, a few mg at a time. You may enjoy them at lower concentrations as than you think.
But tripling the amount of nic in your vape is a sure recipe to get a bit nic sick in my opinion. It probably may be unpleasant but equally it probably won't kill you. I wouldn't ADVISE doing it hat way, but if you must, you must, etc.
Anna