It means you let the bounce clear and see if she comes back into green. If she doesn’t, then she has failed the reduction and the dose would go back up at that time. It might take two cycles for the bounce to clear or it might take up to six. However long it takes, if she doesn’t get back to green, then go back up.
The reason I will be surprised if you don’t have to take the dose back up within the next six cycles is because from what I can see with the tests you have, she wasn’t really doing that great on 1u. The first test on the AT was likely the most accurate and it was 90. The reduction point is below 90 but, without you getting more tests in at night to see what she’s really doing, I’m not willing to risk her safety.
So, watch over the next few cycles and see how she does. She’s going to bounce but you’ll need some data at night to know how low the new dose of 0.75u is taking her. If she isn’t getting back to green after the bounce clears, increase back up to 1u.
Sound good?