In the long-term you will likely lose your hypo awareness symptoms running bg levels so low, as far as I'm aware there's no benefits in running your bg levels in the 4's over running them in the 5's (although I'm happy to be corrected).
Is there scientific data out there to back that statement? I asked genuinely as I'm not aware of any and my only experience is what Ive personally dealt with since my t1 diagnosis 2 years ago.
My levels often stay in the 4.0-5.0 range when I'm on a stricter low carb diet (<10% of total calories) and running 20+ miles a week.
I don't intentionally keep them that low but my body's natural glucagon response seems to function very well. I actually have much better hypo awareness and fewer lows in that environment. To quantify that, I can usually tell as soon as my blood sugar is below 3.8.
In contrast, when I introduce more carbs into my diet (20%+ of total calories) my fasting levels will hover in the 6.0 range, and my basal needs can increase by more than 50% (I currently take 12u of Tresiba and can need more than 20u to keep my fasting blood sugar level).
Long story short- it's not really a choice for me but it's also not a problem (at least for now).
Side note: I attribute my widely ranging insulin needs to glycogen depletion and storage. When my glycogen is depleted my levels remain very low and my sensitivity to carbs is very low (1:15g or lower). When my glycogen storage is full my sensitivity to carbs is much higher (1:8g).