A cut through latch 8's spring carriage, with every number you can change. The spring sits between the printed carriage and the washer under the nut, in series with the TPU seal. Make the loop slacken or the seal take a set, and see how much force the latch keeps and how hard the seal is still pressed.
Pull counts from the moment the rod goes tight with the lid resting on the seal. The shaded area is the work your hand puts in; if the lid lands on the stops, the curve kinks there and only the spring keeps squeezing. Slack walks the latch back down this same curve.
Every 0.1 mm the loop grows costs up to the spring rate times 0.1 mm: with this spring, with the 175 N/mm coil, with no spring at all. While the lid rides on the seal it costs a little less, because the seal springs back and takes up part of it.
With the lid on the stops the gap is fixed, so a seal that takes a set presses less whatever spring you fit. Put the stops a little below where a new seal holds the lid and the spring follows the seal down instead. At 52 % set the seal is still pressed at with the stops where you have them, against with them at 0.8 mm, as on the other latches. Drag stops at and set to compare.
For the same closing force this spring needs of pull under load, against for the coil, and of work against .