I just finished hatching for the first time and I will give you my input.
I did not touch the humidity until lockdown, it hovered between 25 and 40 until then and all of my eggs developed though not all hatched. I did not see veins in all of my eggs until around day 12 or 13, I had some at 7, some at 8 more on 10 etc, so don't give up. The candling pictures look like mine, so I think you are all set.
I stressed and stressed about the humidity prior to lockdown, but then I just decided to let nature take its course and did not touch them until lockdown. I recommend this as it gives peace of mind and works fine for lots of people. This way you can focus on the temperature of the incubator and building your brooder