Your latest 2026/7/16, session #98, routine, that you've achieved 19cm post stretching was part of the key. As huge-girth pointed out, that extra stretching load is needed to increase the fatigue point a bit faster using the Length Master. Pushing hard between the LM and the extender is actually the key to causing additional fatigue in between. Just something to consider as well.
When going between the LM and the extender, you're pushing from the extender at 45 degrees before the LM lacks the pulling traction loading, and acts more like a warm-up tension loading. Switch it around. A quick pulling warmup using your hands, such as the SRT helicopter rotation for 60 seconds in one direction, full strength, and another 60 seconds in the other direction after a good heat application from a hot towel, shower, or heated rice sock. Go straight to the LM to cause immediate tissue breakdown and fatigue, and use the extender to keep the tissue to flag the body to push for immediate repairs in an elongated state.
During the time you keep things elongated with the extender, drink water, especially with electrolytes. It may not sound like anything, but during this period, the body requires mobilisation of blood and resources. Drinking a bit of electrolytes stimulates the release of specific hormones and additional mobility of resources when an emergency flag is raised. If you can, wrap the penis up with a warm towel or a warm heat source, hitting around 101F to 104F (38.3C to 34C). Keeping the tissues even more flexible and warm during the period will push the tissues to engage remodeling progression faster. Think about how your body deals with a cold virus when you're sick, as your body heats up. Unfortunately, your penis is too far of a remote appendage to heat, so the body retracts it instead. By providing that heat source, the body focuses on delivering resources instead of spending useless energy to heat it up.
Try switching the 1st weight loads around. 9lbs, 5lbs, then 7lbs. For the second session, switch to 7lbs, 5lbs, 6lbs, then 4lbs. The light traction loading in between re-programs the body to think that there's no trauma, but longitudinal extension for optimal healing instead. Think of growing pains during your adolescent years or even during evening rest, when your body stretches out. Keep everything elongated as much as possible for the wrapping afterwards. You can use the extender if you're at home at 2.5lbs, or wrap your penis up to have a similar length to the extender whenever possible. Don't wrap too tightly.