With weights around 70-80% my e1RM is still more than 10% to high. I allways see “moved like” around 10% points lower as “actually was”

Sounds like you may have an issue with testing your true 1RM. The “moved like” estimate is based on your velocity. So the bar is not as close to failure as you think. This might be an indication to work with overloading variations more frequently before your next 1RM tests.

So there is hope to move that e1RM some day, great.

Yes, that’s where the trend points. The trick is there is usually some breakdown as you get closer. Wherever it breaks is where your tested 1RM is. 1RM testing is a skill too besides just a show of strength. Partial ROM movements are especially helpful as are reverse bands.