How to find right Flow

Hello, Normally I have no problems with this part of calibration. (So on my Prusas and Bambulabs) But with the Ratrig v4 | can't get the right value. I already printed the orca flow test and there I got the value of 0.92 but the parts are a little bit underextrusioned like 1-2%. So I printed like Ellis guide said 30x30x3mm cubes with 25% infill and 10 top layers and there I would take the 0.95 flow one but then the parts are a little bit overextended on some points (the pictures are all on 0.95 flow) and the other part have 6 top layers