Figuring out humidity doesn't have to be guessing and experimentation.
The best way to know what humidity to incubate at is to either weigh your eggs or track your air cell growth. You want to aim for a certain percentage of weight loss, or a certain size air cell on days 7, 14, and 18. The directions for how to do this are here:
Sally's Incubation Notes,
Start out low--berween 30 and 40%. On day 0, either candle your eggs and trace the air cell, or weigh the eggs to get a base weight.
On day 7, candle and trace or weigh eggs. Then adjust your humidity accordingly. If your weight loss is too high, increase humidity or vice versa. If your egg cells are too small or large, adjust humidity accordingly.
Repeat on day 14. Even in day 18, you can still do some adjusting even as you begin lockdown.