No, the withdrawal is too bad, even when doing it slowly.
I don't think I need it as much for sleep anymore, but yes, I am afraid of insomnia during taper as I wouldn't be able to deal with that, on top of all the other pains. I tried Quetiapine for some months before getting on Mirtazapine. I tried both 25 mg, 50 mg and 75 mg and neither helped me sleep at all, just made me feel "weird and off" (it did help to quiet my racing thoughts though). I have a friend that swears by Quetiapine for sleep though, 25 mg. With meds it's so individual what works and how it works. Even pretty heavy doses of benzos didn't put me down, like Mirtazapine did in the first months. With benzos it would still take me an hour to fall asleep and I would "only" sleep like 7 hours. With Mirtazapine it completely knocked me out to the point where I couldn't stand on my legs 15 minutes after taking it and I would easily sleep 10 hours on it. That says something about how heavily Mirtazapine impacts my system, I think.
I wish I could get off it, but I just don't see how. I wish there was something to counteract the withdrawal, but there isn't, so...