How often can I dye my entire head of hair?

I've dyed my hair ~3 times since July, each time going a little darker (dark brown). The last time I dyed it was mid-September, so it's been a little over a month now, and the roots are already fading (although very slowly). I want to dye it a proper black now, but I'm wondering how truly bad it is for my hair to dye the entire thing this often. For reference, I have very thick, coarse, straight hair, and I have very good hair genes (I've bleached my hair & box-dyed it probably 20+ times since 2017 and it's still in perfect condition with no damage).

Should I wait a few more months to dye my hair black, like maybe January? Or would it probably be okay to do it a little sooner?