How smooth does hull exterior need to be for through-hull fitting sealing?

I am in the process of replacing our through-hull fittings and the hull exterior under where the new flanges will be sat has a couple of very slight indents (there were several scores, that I've filled and faired and this is what's left). I've marked in pen where the new flanges will be sat (and hence most of the sikaflex291!), and am wondering if anybody with more experience could help me with a quick sanity check and let me know whether i need to be doing more filling and fairing, or whether actually once a couple of beads of sealant are applied, the few minor indents won't matter? For reference they're a lot less than a mm deep, I would say the deepest pit is around half a mm deep.