I made a claim that "all other references I could find tend to say that Thrust at Launch...
Your references all describe rockets firing
in air, not
at launch. Granted almost all rockets we build and care about today launch from Earth and fly in air initially. But the LM files entirely in a vacuum, where your references do not generally apply. The LM launch is in vacuum.
Further, your references are concerned with momentum thrust only, which is appropriate when discussing rockets that fly in air. We tune the expansion ratio to optimize momentum thrust for some particular altitude. For most rockets, that's launch altitude. But for others like the space shuttle, that's at a point higher in its trajectory. In vacuum, pressure thrust occurs and is much more pronounced. It provides a significant amount of the thrust in a vacuum, where a properly expanded plume (and therefore optimum momentum thrust) is practically impossible. Because the plume spreads in a vacuum, it's not always the case that an advantage in momentum thrust due to to unimpeded flow outpaces the loss of momentum thrust from incoherent flow. It depends on the precise design of the engine.
Just because
your sources ignore this for the sake of simplicity doesn't mean they don't occur.
This would be similar to the AM trying to launch when almost sealed to the Lander base, which constricts exhaust outflow.
That's not an unreasonable supposition, but then you neglect the augmentation to pressure thrust that occurs. Your references do not equip you to reason about this special problem in rocketry because they are basic explanations offered to a lay audience.
I have seen no references that talk about Thrust being MORE at Launch as a result of these types of Exhaust restrictions.
Asked and answered. It's a condition we eminently tried to avoid, and so no one studied it. It has only become a subject of research lately now that hot staging is becoming possible. NASA was not interested in the thrust effects at LM launch. It was only interested in whether doing so would be dangerous. This is not to say they didn't contemplate the problem. The reference I provided allowed for a 50% overpressure at ignition.
My references have been technical papers written for a technical audience. Your references are pedagogical summaries written for lay persons. They will necessary simply the problem. I should also note that it's disingenuous of you to cite Google AI as a source when you categorically rejected others using it.
I didn't provide these references because I thought this was COMMON KNOWLEDGE, especially for someone with unassailable knowledge like you.
Nice try. Someone who knows this material better than you disputed your understanding of it and the claims you have made regarding it. Now that you finally presented the references you claim you were relying upon, that person can tell you how you were misunderstanding it and misapplying it to your claims. Knowledge is not measured by whether someone agrees with you, and the world is not required to submit to your simplistic understanding. You're still craving that simple, pat answer and easily-digested pat sources.
But in my analysis of the AM launch - I did NOT apply this concept. I kept it the SAME, 15600 Newtons starting immediately at ignition.
And your expectation is wrong for that reason. I have endeavored without success to expand your understanding of how rockets produce thrust under various conditions—nominal and exceptional.
