70% is not too high. I'd consider that pretty close to perfect.
What to do when the humidity goes higher after they start to hatch? Your being in the Pacific Northwest makes it a little harder. I don't know what is in season. If you were on Louisiana this time of year, I'd recommend fresh strawberries. But my suggestion is get a bowl of vanilla ice cream, mix in some fresh fruit, chill, and enjoy the process. It is absolutely normal and not a problem for the humidity to go up after they start to hatch. 85% to 90% is fairly normal for me after they start to hatch, and I normally start lockdown around 65% to 70%.
You want the humidity high during lockdown and especially when they have pipped so they do not dry out and get stuck. The humidity is going to be less than 100% in the incubator. Even if it gets to 95%, which is highly unlikely, by the laws of physics you will not get condensation in there. High humidity will not hurt them.
If the humidity is real high, they may be real slow to dry off after they hatch, but that is not a disaster or really any problem. Once the hatch is over, you can either crack the incubator top to reduce humidity, remove the saucer of water, or put them in a warm brooder. Just don't let them get a chill when transferring them.